is Integer???

[Guest_imported]

How can check if the value I type on a textbox is an integer or not?

thank you.

 

[wushutwist]

Simple way:

String idText = "12";
int id = null;
try {
  id = Integer.parseInt(idText);
}
catch (NumberFormatException nfe) {
  // If Exception then it is not an int. 
  // Do Error Handling.   
}
// If no exception then it is an int
System.out.println(id);

 

[wushutwist]

Sorry, it should be:

int id;

I was originally going to use an Integer. Changed to int but forgot to take out the null assignment.

 

[Guest_imported]

thanks. That was more or less what I was doing except I wasn't using the NumberFormatException. I thought java would have a function to test this like VB, it seems I was wrong

 

[Vepo]

Hi,

There is also a isDigit() method but it is only for characters. Alternative solution would be (but i'd prefer use that NumberFormatException catching):

String s = "12";
if(isdigit(s))
{
System.out.println(s + " is digit."
}
else
{
System.out.println(s + " is not digit."
}

private boolean isdigit(String str_)
{
char[] c = str_.toCharArray();

for(int i=0; i<c.length; i++)
{
if(!Character.isDigit(c))
return false;
}
return true;
}