Java throw Keyword
Example
Throw an exception if age is below 18 (print "Access denied"). If age is 18 or older, print "Access granted":
public class Main {
static void checkAge(int age) {
if (age < 18) {
throw new ArithmeticException("Access denied - You must be at least 18 years old.");
}
else {
System.out.println("Access granted - You are old enough!");
}
}
public static void main(String[] args) {
checkAge(15); // Set age to 15 (which is below 18...)
}
}
Definition and Usage
The throw keyword is used to create a custom error.
The throw statement is used together with an exception type. There are many exception types available in Java: ArithmeticException, ClassNotFoundException, ArrayIndexOutOfBoundsException, SecurityException, etc.
The exception type is often used together with a custom method, like in the example above.
Differences between throw and throws:
| throw | throws |
|---|---|
| Used to throw an exception for a method | Used to indicate what exception type may be thrown by a method |
| Cannot throw multiple exceptions | Can declare multiple exceptions |
Syntax:
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Syntax:
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Related Pages
Read more about exceptions in our Java Try..Catch Tutorial.
