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How to Convert char to int in C++

In this article, we will learn “How to convert char into int  C++,” which is the basic operation in C++. It can be done using various methods, like type casting, standard library functions, or mathematical operations. We will explore different ways to convert char to int.

Using TypeCasting

Typecasting is a feature in the C++ language. It helps to change one type to another type. In this type of casting, we will use the explicit type conversion.

Syntax

Method 1:  In this method, we will use explicit type conversion for converting the character into its corresponding ASCII value(integer).

Program

Output

The time complexity is O(1) and The auxiliary space is also O(1)

Method 2:  If you want to convert a char to an integer value with the same value rather than ASCII. The following program will help you to do this.

The following program demonstrates this code.

Program

Output

Using static_cast

The static_cast function is another function in the C++ programming language. It converts variable data types. The program below demonstrates the static_cast function example.

Program

Output

Using sscanf()

The sscanf() function reads the data from the buffer and stores the value in the respective variable. This function is defined in the <cstdio> header file. We can also use this function to convert characters into integers.

Syntax of sscanf

The following program demonstrates the character-to-integer conversion.

Program

Output

Using stoi

This stoi() function converts a string to an integer value. The following C++ program demonstrates how to convert char to int using the stoi() function.

Program

Output

The atoi() function returns an integer value. If this function successfully executes otherwise, this function will be returned 0. The following program demonstrates the C++ program to convert a char to an integer using teh atoi() function.

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Using stringstream

A string stream allows you to associate a string object with a stream, allowing you to read from the string. If you want to use stringstream, we need to include the sstream header file. This class helps us to process input. The following program demonstrates the C++ program to convert char to int using stream.

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Example with Full code in C++

The following program demonstrates the full Conversion code in char to integer in C++ language.

Program

Output

Converting char Value to int Adding 0

We can convert char to int by adding the 0. First, we initially typecast the character to an integer using the int(), and later, we will add 0 to the typecased value.

Program

Output

stoi() Function vs atoi() Function

The following table differentiates stoi() functions and atoi() functions.

Conclusion

In this article, we learned how to convert characters to integers in C++. C++ is an object-oriented programming language that has many built-in functions in this programming language for doing this. We also saw the explicit typecasting in this article, which converts data type from one type into another type manually.