how to throw error in java code example
Example 1: throw io exception java
public static void foo() throws IOException {
// some code here, when something goes wrong, you might do:
throw new IOException("error message");
}
public static void main(String[] args) {
try {
foo();
} catch (IOException e) {
System.out.println(e.getMessage());
}
}
Example 2: in java how to throw exception from function
public void doChangePin(int oldPin, int pin) throws Exception { //need to add throws followed by exception name
if (oldPin == pinCode) {
pinCode = pin;
} else {
throw new Exception("some message"); //throwing the exception by creating its new object
}
}
Example 3: java how to throw exception
public class ThrowException{
public static void main(String [] args) throws Exception{
//throws Exception line is needed if not using try-catch block
throw new Exception("Errmessage");
}
}
Example 4: java throw an exception
public static void main(String[] args) {
Scanner kb = new Scanner(System.in);
System.out.println("Enter a number");
try {
double nb1 = kb.nextDouble();
if(nb1<0)
throw new ArithmeticException();
else System.out.println( "result : " + Math.sqrt(nb1) );
} catch (ArithmeticException e) {
System.out.println("You tried an impossible sqrt");
}
}
Example 5: throw keyword in java
Generally JVM throws the exception and
we handle the exceptions by
using try catch block. But there are
situations where we have to throw
userdefined exceptions or runtime exceptions.
In such case we use throw keyword
to throw exception explicitly.
Syntax : throw throwableInstance;