Keywords in C: Properties, Usage, Examples & More

Updated on October 28, 2024

Article Outline

What are Keywords in C?How Many Keywords Are There In C Language?Categories of Keywords in C Different Keywords in C Properties of C Keywords Difference between Identifiers And Keywords In C Applications of Keywords in C Common Mistakes with Keywords in C Conclusion FAQs

Understanding keywords is crucial for writing syntactically correct C programs. These are reserved words or some predefined identifiers that make the compiler understand the code written and decide the flow of execution in the program. Keywords help determine the logic of programming and control structures. Thus, they are quite crucial to be mastered by any C programmer.

The keywords are reserved words in any programming language, the same is true for C language. They have a predefined meaning and are most important in constructing correct statements following the rules of syntax for any C program. Keywords are the basic building block for expressing logic and control flow through C programs. Since it is primarily reserved, therefore, it may not be employed as a variable name, function name, or any other identifier within C programming.

In this article, we will learn in-depth about Keywords in C, including their different types, properties, syntax, usage with different examples, and more.

What are Keywords in C?

Keywords in C are reserved words with special meanings and purposes. The compiler interprets keywords differently because they have special meanings. Keywords cannot be used as program identifiers because they are part of the syntax. Keywords are Integral parts of the C language; they do a lot to shape the programming style. Since keywords are reserved, they cannot be used as identifiers (e.g., variable names, functions, etc.) as their primary purpose lies elsewhere.

The C language is case-sensitive, which means that keywords written in capital (like Switch) are handled differently than keywords written in lowercase (switch). These keywords are essential for defining function declarations, data types, control structures, and other fundamental components in C programs. Keywords are not only reserved in C language but also in other programming languages including Java, JavaScript, etc.

Characteristics of Keywords in C

Reserved words: Keywords in C are reserved and cannot be used as identifiers in the program that you write.
Fixed Functionality: Keywords defined for C have fixed functionality. The behaviour is mandated and cannot be changed by the programmer for any valid implementation of the C programming language standard.
Case-Sensitive: C keywords are case-sensitive, i.e., all keywords must be written in lowercase (such as int, for, if, etc.).
Predefined in the Compiler: Keywords are pre-defined and recognized by the compiler, as they are imperative to control flow, data types, and structure.
Limited in Number: The count of keywords is fixed in C (32 in ANSI C). The keywords make up the building blocks of the syntax and structure of C.
Specific Use in Context: Keywords serve a specific role in context, much like variable declarations (int, float), control structure definitions (if, for, while), or user-defined type creations (struct, enum).

How Many Keywords Are There In C Language?

In C programming, there is a total of 32 keywords, as defined by the ANSI C standard. Some compilers or language standards may have a different number, however, as per C99, the following C keywords are used:

break	case	char	const	auto	continue	default	do
double	else	enum	extern	float	for	goto	if
int	long	register	restrict	return	short	signed	sizeof
static	struct	typedef	union	unsigned	void	volatile	while

These are the 32 keywords in C, which have different meanings and special purposes. These keywords in C are further categorised based on their functionality and usage.

Categories of Keywords in C

Data Type Keywords: These are the keywords that specify the different data types available in C. This type includes int, char, float, double, void, struct, union, and enum.
Control Flow Keywords: This type comprises keywords that facilitate the control of the flow of execution in a program. Such types include: if, else, switch, for, while, do, and break.
Type Modifier Keywords: These keywords modify the type of variables. Examples of this type include signed, unsigned, short, and long.
Function Keywords: These keywords deal with function definitions and calls. Examples of this type include return, inline, and typedef.
Other Keywords: Some keywords serve specific purposes in C programming. Examples of this type include const, volatile, sizeof, goto, and restrict.
Storage Class Keywords: These keywords define the scope and lifetime of variables. Examples of this type include auto, register, static, and extern.

Now we will understand each keyword in detail one by one, along with its syntax and examples.

Different Keywords in C

1. auto

The auto keyword in C language specifies the automatic variables. Usually, the local variables contained within a function are classified as automatic variables which implies the variables are given storage space in the stack which is removed after the function exhausts. The auto keyword is very rarely used plainly for the reason that it is the standard storage class of local variables. It is indeed useful whenever there is a need for enhancing the readability of the code structure as it explains the time the variable is going to be active.

Syntax:

auto data_type variable_name;

Example:

#include <stdio.h>

int main() {

auto int num = 30; // auto is optional here

printf("The number is: %dn", num);

return 0;

}

Output:

The number is: 30

Explanation:

In this example, we define a local variable’s type automatically based on the assigned value. In this case, num is an integer.

2. break

The break keyword refers to a control flow statement which is designed to cut off the import of a loop or switch statement earlier than the statement was intended to. Any time a break statement is encountered in a loop that is usually for, while, or do while, such a statement while the execution is in that loop, controls transfer to the next statement, which follows the loop.

Syntax:

break;

Example:

#include <stdio.h>

int main() {

for (int i = 1; i < 20; i++) {

if (i == 8) {

break; // Exit the loop when i is 5

}

printf("%d ", i);

}

return 0;

}

Output:

1 2 3 4 5 6 7

Explanation:

In this example, the loop exits immediately when a specific condition is met, i.e., when i == 3.

3. case

The case keyword is used on the switch statement and asserts the value possessed by a variable or a certain expression aimed at imperative execution. Each of the cases carries a constant and if that constant is inclusive of the switch expression, then its related block is executed.

Syntax:

case constant_expression:

Example:

#include <stdio.h>

int main() {

int num = 4;

switch (num) {

case 1:

printf("Onen");

break;

case 2:

printf("Twon");

break;

default:

printf("Othern");

break;

}

return 0;

}

Output:

Other

Explanation:

In this example, it matches the variable against specific cases in a switch statement and executes code when the value of num matches a case.

4. char

The char keyword in C is used to define a character type variable, which typically occupies one byte of memory. Individual characters, such as letters, numbers, and symbols, represented by ASCII values, are stored in this data type. The char type is essential for managing textual data since it may define strings, or arrays of characters when paired with other constructions.

Syntax:

char variable_name;

Example:

#include <stdio.h>

int main() {

char letter = 'J';

printf("The character: %cn", letter);

return 0;

}

Output:

The character: J

Explanation:

In this example, the letter holds the character ‘J’.

5. const

In C, a constant variable is created by using the const keyword – signifying that upon its initialization, the value cannot be altered. This is important for creating read-only variables that enhance the code’s readability and stability by ensuring that no changes are made inadvertently across the code.

Syntax:

const dataType variableName = value;

Example:

#include <stdio.h>

int main() {

const int num = 10;

// num = 20; // This would cause a compile-time error

printf("Constant Number: %dn", num);

return 0;

}

Output:

The constant number: 50

Explanation:

In this example, we have defined a const number 50, which means a fixed value.

6. continue

In loops, the remaining code in the current iteration is skipped and the next iteration is executed straight away by the use of the continue keyword. Control immediately moves to the loop’s condition upon encountering continue, enabling reevaluation. This is helpful when certain circumstances call for omitting particular iterations while preserving the general structure of the loop.

Syntax:

continue;

Example:

#include <stdio.h>

int main() {

for (int i = 1; i < 10; i++) {

if (i == 4) {

continue; // Skip the iteration when i is 2

}

printf("%d ", i);

}

return 0;

}

Output:

1 2 3 5 6 7 8 9

Explanation:

In this example, the continue keyword is used which skips the rest of the current loop iteration and proceeds with the next. Here, when i == 3, it skips the printf statement.

7. default

The default keyword within the switch statement allows the instruction that appears after this keyword to be executed if the value of the expression being evaluated does not equate to any case label. The default case is the last and will always be checked and so will the default case will allow for handling unexpected or undefined input without writing many tests of conditions.

Syntax:

default:

Example:

#include <stdio.h>

int main() {

int num = 5;

switch (num) {

case 1:

printf("Onen");

break;

case 2:

printf("Twon");

break;

default:

printf("Default casen");

break;

}

return 0;

}

Output:

Default case

Explanation:

In this example, we have used the default, which provides a default action in a switch when no cases match. Outputs a message if num is neither 1 nor 2.

8. do

The do keyword is associated with the beginning of the do-while loop. That is one of the control structures that enables the provision of executing a block of statements at least one time before a condition is tested.

Syntax:

do { /* code */ } while (condition);

Example:

#include <stdio.h>

int main() {

int i = 0;

do {

printf("%d ", i);

i++;

} while (i < 10);

return 0;

}

Output:

0 1 2 3 4 5 6 7 8 9

Explanation:

In this example, `do` executes the loop body at least once before checking the condition. Prints numbers 1 through 5, even though the condition is checked after the loop.

9. double

The double keyword appears when double precision floating point variables are declared in C. These variables can store decimal value numbers that are broader and more precise than the float type. A double is more often than not situated in 8 bytes of memory and can take on large numbers or small numbers which makes it possible to do complex calculations that need high accuracy such as scientific work, financial calculation, or any work in which precision is critical, round-off errors will spoil the result.

Syntax:

double variable_name;

Example:

#include <stdio.h>

int main() {

double num = 5.65;

printf("Double Number: %fn", num);

return 0;

}

Output:

Double Number: 5.650000

Explanation:

In this example, double is used which defines a variable of double-precision floating-point type. The variable num holds a large decimal value.

10. else

The else keyword is used together with the ‘if’ statement structures to execute alternative code when the conjunction clause in the ‘if’ statement is evaluated as false. It is a useful word since it allows one to use more than one way in which a program works depending on the time where the program is executed.

Syntax:

else { /* code */ }

Example:

#include <stdio.h>

int main() {

int num = 10;

if (num < 25) {

printf("Less than 10n");

} else {

printf("10 or moren");

}

return 0;

}

Output:

Less than 10

Explanation:

In this example, the else keyword is used that executes when the if condition evaluates to false. Prints num as odd if it is not divisible by 2.

11. enum

The enum keyword is a declaration specification that is used for defining enumerations, or in other words the enumeration is a user-defined data type comprising integral constants. Enums are appropriately used in situations where a certain variable can only have a single out of a finite number of possible values.

Syntax:

enum EnumName { value1, value2, ... };

Example:

#include <stdio.h>

enum Days { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday };

int main() {

enum Days today = Friday;

printf("Today is day number: %dn", today);

return 0;

}

Output:

Today is day number: 5

Explanation:

In this example, we have used the enum keywords, that define an enumeration, a user-defined type consisting of named integral constants. Here, days represent the days of the week.

12. extern

The extern keyword is an instruction that is used to declare c-elements (variables, functions, etc.) that have been defined in some other translation unit (i.e. some other source file). It is particularly useful where there is a need to control the visibility of variables and function availability in several files of a C program.

Syntax:

extern data_type variable_name;

Example:

// file1.c

#include <stdio.h>

int sharedVar = 250;

// file2.c

extern int sharedVar;

int main() {

printf("Shared Variable: %dn", sharedVar);

return 0;

}

Output:

Shared Variable: 100

Explanation:

In this example, we have used the extern keyword which declares a variable that is defined elsewhere. The actual variable num is defined outside the current file.

13. float

The float keyword is used to define single-precision floating-point variables in C, which can store decimal numbers. A float typically occupies 4 bytes of memory and provides a range of values that can represent real numbers, but with limited precision compared to double.

Syntax:

float variable_name;

Example:

#include <stdio.h>

int main() {

float num = 5.75f;

printf("Float Number: %fn", num);

return 0;

}

Output:

Float Number: 5.750000

Explanation:

In this example, the num variable is a float type that holds a value with a decimal.

14. for

The for keyword is used in order to create a for loop, that is, one of these control structures with the repetition of execution of a block of code based on some specified condition. This keyword allows easier iteration over values in a range by including initialization, checking of a condition, and increment/decrement all in one line.

Syntax:

for (initialization; condition; increment)

Example:

#include <stdio.h>

int main() {

for (int i = 0; i < 10; i++) {

printf("%d ", i);

}

return 0;

}

Output:

0 1 2 3 4 5 6 7 8 9

15. goto

The goto keyword is a control flow statement that allows an unconditioned transfer from the current part of the program to some other place, identified by its label.

Syntax:

goto label;

Example:

#include <stdio.h>

int main() {

int i = 1;

label:

printf("No. %d, ", i);

i++;

if (i < 15) {

goto label; // Jumps back to the label

}

return 0;

}

Output:

No. 1, No. 2, No. 3, No. 4, No. 5, No. 6, No. 7, No. 8, No. 9, No. 10, No. 11, No. 12, No. 13, No. 14,

16. if

If you want to create a conditional statement enabling making decisions in the program, the `if` statement can be used. The if statement checks the condition and executes the block of code only if the condition is satisfied.

Syntax:

if (condition) { /* code */ }

Example:

#include <stdio.h>

int main() {

int num = 15;

if (num > 5) {

printf("It is a positive numbern");

}

return 0;

}

Output:

It is a positive number

17. int

The int keyword allows C programmers to establish variables of integer type, which is identified by the ability of whole numbers without the decimal point.

Syntax:

int variable_name;

Example:

#include <stdio.h>

int main() {

int myNum1 = 40;

int myNum2 = 50;

int myNum3 = 60;
 
printf("This is an integer number: %dn", myNum1);

printf("This is an integer number: %dn", myNum2);

printf("This is an integer number: %dn", myNum3);

return 0;

}

Output:

This is an integer number: 40

This is an integer number: 50

This is an integer number: 60

18. long

The long keyword in C is used to define long integer type variables, which can store larger whole numbers compared to the standard int type.

Syntax:

long variable_name;

Example:

#include <stdio.h>

int main() {

long myNum1 = 40L;

long myNum2 = 50L;

long myNum3 = 60L; 

printf("This is a long number: %dn", myNum1);

printf("This is a long number: %dn", myNum2);

printf("This is a long number: %dn", myNum3);

return 0;

}

Output:

This is a long number: 40

This is a long number: 50

This is a long number: 60

19. register

The Register keyword in C requests the compiler, whenever possible, to physically place a given variable in a register instead of the RAM.

Syntax:

register data_type variable_name;

Example:

#include <stdio.h> 

int main() {

register int myNum1 = 125;

register int myNum3 = 135;

register long myNum2 = 145L; 

printf("Register Number: %dn", myNum1);

printf("Register Number: %dn", myNum2);

printf("Register Number: %dn", myNum3);

return 0;

}

Output:

Register Number: 125

Register Number: 145

Register Number: 135

20. return

It serves the purpose of inserting the output statements that define what a particular function will return when called from some other functions.

Syntax:

return expression;

Example:

#include <stdio.h>

int sum(int a, int b) {

return a + b; // Returns the sum of a and b

}

int main() {

int res = sum(15, 45);

printf("The sum of two numbers is: %dn", res);

return 0;

}

Output:

The sum of the two numbers is: 60

21. short

The short keyword is used to define short integer type variables in C, which can hold smaller whole numbers compared to the standard int type.

Syntax:

short variable_name;

Example:

#include <stdio.h>

int main() {

short num = 10000;

printf("Short Number: %hdn", num);

return 0;

}

Output:

Short Number: 10000

22. switch

The switch keyword creates a multi-way branch statement that allows a variable to be tested for equality against a list of values, each specified in a case statement. This is using such a construct advantageously to write code that will be clearer and easier to read than what could have been achieved through a sequence of if-else statements when many values are possible for an expression.

Syntax:

switch (expression) { case value: /* code */ default: /* code */ }

Example:

#include <stdio.h>

int main() {

int n = 3;

switch (n) {

case 1:

printf("This is Javan");

break;

case 2:

printf("This is C++n");

break;

case 3:

printf("This is Pythonn");

break;

default:

printf("This is not a programming languagen");

break;

}

return 0;

}

Output:

This is Python

23. signed

The signed keyword indicates that a variable can hold both positive and negative values, and by default, a number is always signed.

Syntax:

signed data_type variable_name;

Example:

#include <stdio.h>

int main() {

int a = -10;   // Signed integer, can hold negative values

int b = 20;    // Signed integer, can hold positive values

printf("Signed integer a: %dn", a);

printf("Signed integer b: %dn", b);

return 0;

}

Output:

Signed integer a: -10

Signed integer b: 20

24. sizeof

In C, the `sizeof` operator is used to return the size of a datatype or variable in bytes at compile time. It can be used to determine data structure sizes, and memory allocation, and ensure system portability.

Syntax:

sizeof(data_type/variable);

Example:

#include <stdio.h>

int main() {

int n1;

long n2;

float n3;

printf("Size of int: %zu bytesn", sizeof(n1));

printf("Size of long: %zu bytesn", sizeof(n2));

printf("Size of float: %zu bytesn", sizeof(n3));

return 0;

}

Output:

Size of int: 4 bytes

Size of long: 8 bytes

Size of float: 4 bytes

25. static

In C, the static keyword plays a pivotal role by primarily establishing the lifetime and visibility of variables and functions. It can be used for the creation of two types of static variables – local and global.

Syntax:

static data_type variable_name;

Example:

#include <stdio.h>

void counter() {

static int count = 0; // Retains value between calls

count++;

printf("Count: %dn", count);

} 

int main() {

counter();

counter();

return 0;

}

Output:

Count: 1

Count: 2

26. struct

The struct keyword defines the user-defined data types that group the variables of different types under a single name. It allows developers to create complex data types of real-world entities by encapsulating the related data.

Syntax:

struct StructName {

dataType member1;

dataType member2;

};

Example:

#include <stdio.h>

struct Sum {

int a;

int b;

}; 

int main() {

struct Sum s;

s.a = 10;

s.b = 20;

printf("Sum is: (%d)n", s.a + s.b);

return 0;

}

Output:

Sum is: (30)

27. typedef

The typedef keyword is pivotal for providing the programmer with new type names or synonyms aimed at improving code style and making the formation of complex declarations easier to some extent. By creating new types, the programmer can make his or her codes better and simpler, especially when dealing with pointers, structures, and function pointers.

Syntax:

typedef existing_type new_type_name;

Example:

#include <stdio.h>

typedef unsigned long unlong;

int main() {

unlong myNum = 12345678910;

printf("Unsigned Long Number: %lun", myNum);

return 0;

}

Output:

Unsigned Long Number: 12345678910

28. union

The union keyword is used when one needs to create complex data types that can store several variables but at present only hold one. A union allows several variables to occupy the same memory space which is useful especially where less space is needed.

Syntax:

union UnionName { data_type member1; data_type member2; ... };

Example:

#include <stdio.h>

union Data {

int iVal;

float fVal;

char cVal;

};

int main() {

union Data d;

d.iVal = 30; // Setting int value

printf("Integer: %dn", d.iVal);

d.fVal = 3.14; // Now, setting float value

printf("Float: %fn", d.fVal); // intValue is now overwritten

d.cVal = 'A'; // Now, setting char value

printf("Character: %cn", d.cVal); // cVal is now overwritten

return 0;

}

Output:

Integer: 30

Float: 3.140000

Character: A

29. unsigned

The unsigned keyword is a data type modifier that specifies that the respective variable can only hold positive values. This increases the range of possible values by not using a sign bit.

Syntax:

unsigned data_type variable_name;

Example:

#include <stdio.h>

int main() {

unsigned int x = 50;    // Unsigned integer, can only hold non-negative values

unsigned int y = -10;   // This will cause a large positive value due to overflow 

printf("Unsigned integer x: %un", x);

printf("Unsigned integer y: %un", y); 

return 0;

}

Output:

Unsigned integer x: 50

Unsigned integer y: 4294967286

30. void

The void keyword indicates that a function does not provide a return type and a pointer is not associated with a type of data. Void is employed to declare such a type of function, which will be executed carefully, but which will not return to the calling function any information in any form.

Syntax:

void function_name(parameters);

Example:

#include <stdio.h>

void greet() {

printf("Hello, HeroVide!n");

}

int main() {

greet(); // Calling function

return 0;

}

Output:

Hello, HeroVide!

31. volatile

The volatile keyword tells the compiler that such variables may change in unpredictable ways. For example, a variable could have its value altered by the operating system, the hardware, or even some other thread running in parallel. In practice, this keyword often entails that the variable will be accessed frequently.

Syntax:

volatile data_type variable_name;

Example:

#include <stdio.h>

volatile int counter = 0; 

int main() {

// Simulate a counter that could change unexpectedly

for (int i = 0; i < 10; i++) {

counter++;

}

printf("Counter: %dn", counter);

return 0;

}

Output:

Counter: 10

32. while

The while keyword implements the loop, a specific code block is executed repetitively within it until a certain condition is no longer true. This condition is checked just before each iteration, which makes it possible to create loops that may be executed zero, one, or many times.

Syntax:

while (condition) { /* code */ }

Example:

#include <stdio.h> 

int main() {

int i = 0;

while (i < 20) {

printf("%d ", i);

i++;

}

return 0;

}

Output:

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Properties of C Keywords

C keywords have specific differences that are important properties of the programming language:

Reserved Words: Keywords are reserved and cannot be used as identifiers. This improves the later use of defined functions and prevents any conflicts.
Case Sensitivity: C Keywords are case-sensitive. For example, int and Int have completely different meanings, with only int recognized as a keyword.
Fixed Meaning: Every keyword has a fixed meaning, as specified by the C language standard. For example, the keyword return always signifies the end of the function; it can also, if necessary, return some value.
Syntactical Role: As Keywords are an integral part of C program syntax, they assist in determining the control flow along with defining data types and memory allocation, among other purposes.
Compile-Time Errors: Improper keyword usage and identifier conflict with a keyword cause an error and will be thrown by the compiler. This shows how much emphasis proper usage has in code.

Difference between Identifiers And Keywords In C

While working with Keywords in C, programmers often get confused with Identifiers in C. Here is a key difference between Identifiers and Keywords in C:

Aspect	Identifiers	Keywords
Definition	Identifiers are the names used by the programmer for variables, functions, arrays, etc.	Keywords are the predefined or reserved words with special meaning in C.
Defined by	Defined by the programmer.	Defined by the C language itself.
Usage	Used to name variables, functions, arrays, structures, etc.	Used to define the syntax and structure of C programs
Customization	Identifiers can be customised and chosen by the user.	Keywords cannot be changed or redefined by the programmer, as they are defined by C language.
Beginning	Identifiers cannot start with a number; only a letter or an underscore (_) can.	Keywords cannot contain underscores or unusual characters and must begin with a letter.
Case Sensitivity	It is case-sensitive.	It is also case-sensitive
Number Allowed	Identifiers can contain alphabets, digits, and underscores, but cannot start with a digit.	No numbers or underscores are allowed, strictly alphabetic.
Length	Typically no fixed length limit (though compilers may set practical limits).	Fixed words, predefined by the language standard
Examples	int count, float price, main(), etc.	if else, for, return, int, void, etc.

Applications of Keywords in C

Programming effectively in C requires a mastery of its keywords, which are used in many different applications. Let’s examine some of the typical uses of keywords in C programs in more detail.

Control Structures: Several keywords such as if, else, for, and while provide mechanisms for designing execution control and repeated processing which form the core of algorithm development.
Data Handling: Some keywords in C such as struct, union, and enum, help to define and handle compound data types which make it easier for programmers to represent objects in the real world.
Memory Management: Keywords such as static, extern, and register permit the control of the scope and the retention of a variable as well as the space in use.
Storage Classes: The keywords such as auto, register, static, and extern, indicate how the storage class of various variables and functions and their contents in the function body is defined.
Type Definitions: The keyword `typedef`, allows the developers to enhance the code construction so that it is easier to change complex data types into simpler ones that are more functional.
Functionality Control: Keywords such as `return`, and `void`, are some of the key terms used in controlling function behaviour and function return features, and enable the use of modular programming. Globally, the `extern` keyword is commonly used to pledge an existent image of a defined body in other books.
Concurrency Control: The use of the `volatile` keyword is very crucial where more than one thread is being executed as it focuses on the main targeted address preventing variables shared from being optimised and updated easily.

Also Read: C Programming Interview Questions and Answers

Common Mistakes with Keywords in C

Programmers working with keywords in C usually run into some challenges and make mistakes. Below are some mistakes to avoid:

Ignoring Case Sensitivity: In C, keywords are case-sensitive. Using any other case than the one defined (e.g. Int in place of int) will be flagged and prevent completion.
Treating keywords as Identifiers: This will not work and will bring about conflicts and compilation errors. Do not use keywords as variable or function names.
Scope Rules: Most of the programmers do not bother to comprehend the scope of storage class keywords such as `static` and `extern`. A misconception of this nature can impair programming logic such as being able to reach a variable where one expects to find it only to learn that it’s not available.
Mixing up data types: When you use the keywords `signed` or `unsigned` or `short` or `long` be sure that such keywords are used in the right combinations for the right type of data. Misuse can lead to improper data handling.
Not Being Careful with Volatile Variables: In multithreading applications, failing to declare shared variables as volatile may result in incorrect behaviour due to compiler optimizations.
Writing Excessively in goto: While the goto keyword is available, overusing it can lead to code that is difficult to read and maintain. Instead, use structured control flow constructs like loops and functions.

Conclusion

To sum up, learning keywords in C is essential to being a proficient programmer and knowing the language. Keywords improve the readability and maintainability of your code, along with its syntax definition and organisation of your programs. You may create readable, logical code that is simple to comprehend by utilising keywords like if, for, struct, and union.

As you delve deeper into C programming, using keywords becomes your day-to-day task adding them into your programs. To ensure that you fully grasp how keywords function within the language, try out the examples discussed in this article, make changes to them, and write your programs.

FAQs

What are the 32 reserved keywords in C programming?

C programming language has 32 reserved words known as keywords that possess certain meanings in most programming languages and cannot be used as identifiers of variables, functions, or any other entities. Some keywords are referred to as control structures like if, else, while, for, switch, and case; data types like int, char, float, double, and some are the other keywords in C and there are more keywords.

What is the use of the `this` keyword in C?

A `this` keyword is not used. This keyword can be found in C++ and Java languages only where it indicates the current instance of a class. This is not in C because it is a structured or procedural programming language that encompasses no object-oriented features.

Why are keywords used in C?

The keywords in C assign the program its structure and control flow elements. They also specify the operations and instructions or data types that can be incorporated into the code. The basic keywords like `if`, `else`, and `switch` are for making decisions, and control of program flow, while int, char, and float are the basic keywords that define variable types. Other types include `return` and `void` keywords that control the flow and output of the function.

Is main a keyword in C?

No, `main` is not a keyword in C. It is a special name for a function where the execution of any C program starts. The main() function is required in every C program as it serves as the basic entry point into the program.

What do you understand by the term data type in C?

In C, a data type defines the type of data that can be stored and manipulated within a program. It informs the compiler about the size of the data, the range of values that can be stored, and the operations that can be performed on that data. There are several primary data types in C, including integers (int), floating-point numbers (float, double), and characters (char).

Updated on October 28, 2024

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