help wanted

[david hu]

How to check whether the string entered in the text field is consisted of only digit letters

[Valentin Crettaz]

you can maybe try to convert it to a number and if no NumberFormatException is thrown then there are only digits.

...
String text = textfield.getText();
int number=0;
try {
  number = Integer.parseInt(text);
  // only digits
} catch (NumberFormatException nfe){
  // not only digits
}

Another method is to check if every character of the String is a digit or not

public boolean testForDigit(String text){
    char[] textArray = text.toCharArray();
    for(int i = 0 ; i < textArray.length ; i++ ){
        if(!Character.isDigit(textArray[i]))
            return false;
    }
    return true;
}

HIH

------------------
Valentin Crettaz
Sun Certified Programmer for Java 2 Platform

[Maulin Vasavada]

hi david,
it's easy.. just implement KeyListener on the text field and on each ket stroke check the "keyChar" property of the KeyEvent using getKeyChar() method. check it is between 0-9 and you are done.
regards,
maulin.