Difference Between Throw and Throws in Java

In everyday life, tenses are the sole distinction between throws and throws in Java. However, these two are significantly distinct and are employed for various activities in the computer language Java. The Java language’s exception handling uses the terms throw and throws in java.

The ‘Throw’ is a keyword used to give an instance of exception explicitly in the program that the programmer has manually created to JVM whereas the ‘throws’ is a keyword used to give the responsibilities of exception handling, occurred in the method to the caller method. Let’s deep dive into the major difference between throw and throws in detail.

Learn about the following in the upcoming sections:

What is Throw?

To throw the exception explicitly from the method or any other piece of code, utilize Java’s throw keyword. Either a checked or an unchecked exception may be thrown. Throwing custom exceptions is the major use of the throw keyword. The throw keyword is useful when you wish to raise an exception in your code depending on specified criteria. 

Throw Syntax

For example:

Output:

Explanation: 

The validateMarks() function, which accepts an integer value as a parameter, was developed in this example. If the grade is less than 80, the Arithmetic Exception exception is thrown; otherwise, the message stating you are an Oracle-certified professional is printed. 

Throw Examples

Here is an example of throws in Java:

if (balance < withdrawAmount) {
    throw new InsufficientBalanceException("You have insufficient balance");
}

If the balance in the code above is lower than the withdrawn amount, the term Throw is used to raise an InsufficientBalanceException. The caller code will handle the Exception in a “try-catch” block. You will then get an error notice that reads, “You have insufficient balance,” once you have completed this.

What are Throws?

The throws keyword is used to throw an exception object implicitly. The method signature uses the throws keyword. It is possible to define several exception types in a method signature, which should be comma separated. The method is not responsible for handling the Exception when the Throws keyword is used to specify a method. However, it gives it to the caller code instead. The caller code must either declare the Exception in its method signature utilizing the Throws keyword or manage it using a “try-catch” block.

Throws Syntax

For example:

Output:

Explanation: 

In this case, the programmer explicitly declares that the code may be dangerous by throwing an exception within the procedure. If the file described above is not created initially or gets deleted, the programmes above will throw an exception. 

Throws Examples

This is an example of throws in Java.

public void withdraw(double amount) throws InsufficientBalanceException {
   if (balance < withdrawAmount) {
       throw new InsufficientBalanceException("You have insufficient balance");
   }
   // ...
}

The Throws InsufficientBalanceException method signature in the code example above indicates that the withdraw method may throw an InsufficientBalanceException. The throwing code must either declare the Exception in its own method signature using the throws keyword or catch it using a try-catch block.

Differences Between Throw and Throws

Here is the key difference between throw vs throws in detail:

Also read about : Types of Inheritance in Java

Difference Between throw and Throws with Examples

There are many differences between throw vs throws keywords. Differences between throw and throws examples are given below:

Examples of Java throw

Examples of Java throws

Use of Throw and Throws in Java

There is various difference between throw and throws in java in terms of their uses. The terms throw vs throws in Java both have to do with managing mistakes and exceptions, although they serve distinct functions:.

1. Throw: To create an exception or error in a programme, use the “throw” keyword. If an error condition is found, it is utilized within a method to throw an exception. For instance, a method can use “throw” to create an exception and notify the method’s caller if it gets erroneous input from a user or external system.
2. Throws: The exceptions that a method may throw are listed using the “throws” keyword. It serves as a reminder in the method signature that the method is capable of throwing one or more different exception kinds. This enables the method’s caller to prepare for any exceptions and handle them correctly. For instance, if a method does an action that could cause a checked exception, it should use “throws” in its method signature to indicate the Exception.

Read: Java Operators

Throws vs Throws: How to Choose between Throw and Throws?

The following criteria will assist you in deciding between throw vs throws in Java:

1. When you wish to create an exception or error in your code, use the “throw” keyword. When an error situation has been found, and you want to alert the method’s caller, you would use the word “throw” within a method.
2. When you wish to list the exceptions that a method may throw, use “throws.” To indicate that the method may throw one or more different sorts of exceptions, you would include the word “throws” in the method signature. This enables the method’s caller to prepare for any exceptions and handle them correctly.

Purpose of Error Handling in Java

Error handling makes it possible to handle hardware and software problems gracefully and enables interrupted execution to continue. Either the programmer creates the appropriate codes to manage issues or uses software tools to handle errors when it comes to error handling in software. When mistakes cannot be categorized, they are often handled by returning unique error codes. For some applications, specialized programmes called error handlers can assist in managing errors. These programmes may foresee mistakes, assisting in recovery without terminating the programme.

Read about: Access modifiers in java

Conclusion

In this guide we have learned about the major differences between throw and throws in java. Developers may employ throws and throws in Java effectively to write Java code that is more durable, dependable, and simple to maintain. They are crucial for writing code that can successfully manage unforeseen circumstances and significantly manage exceptions and failures in Java programmes. Also check out Hero Vired Business Analytics and Data Science Course.