Using an if statement to test if JTextField is an integer

Question

I want my program to be able to tell if what is inside my two JTextFields is an integer or a String.

CODE

          public void actionP         


        

Answer 1

Not sure exactly where in your code the test is being performed, but you can use this method to determine if a String is an integer:

public static boolean isInteger(String s) {
    try { 
        Integer.parseInt(s); 
    } catch(NumberFormatException e) { 
        return false; 
    }
    // if exception isn't thrown, then it is an integer
    return true;
}

Less expensive none exception based way, assuming your code does not need to throw an exception:

public static boolean isInt(String s){
        for(int i = 0; i < s.length(); i++){
            if(!Character.isDigit(s.charAt(i))){
                 return false;
            }
        }
        return true;
}