In Java, the throw and throws keywords are used to handle exceptions. The throw keyword is used to explicitly throw an exception, while the throws keyword is used to declare that a method may throw an exception. Here’s an explanation of each keyword with examples:
throw keyword
The throw keyword is used to explicitly throw an exception. This can be useful in situations where you need to handle a specific error condition that is not automatically detected by the Java runtime. Here’s an example:
public static int divide(int a, int b) {
if (b == 0) {
throw new ArithmeticException("Cannot divide by zero");
}
return a / b;
}In this example, the divide method checks if the second argument is zero. If it is, the method throws an ArithmeticException with the message “Cannot divide by zero”. This allows the program to gracefully handle this error condition and prevent the program from crashing.
throws keyword
The throws keyword is used to declare that a method may throw an exception. This allows callers of the method to handle the exception themselves, rather than having the method handle the exception itself. Here’s an example:
public static int divide(int a, int b) throws ArithmeticException {
if (b == 0) {
throw new ArithmeticException("Cannot divide by zero");
}
return a / b;
}In this example, the divide method is declared with the throws ArithmeticException clause. This indicates that the method may throw an ArithmeticException. Callers of the method must either handle the exception themselves or declare that they may also throw an ArithmeticException.
The throw and throws keywords are powerful tools for handling exceptions in Java. By using these keywords, you can write more robust and reliable code that can handle a wide variety of error conditions.