JavaScript isNumeric function

Question

I am writing a Javascript function to validate a user input. The condition is that, the data should have at least one number.

var userName = "abcde200"

function isNumeric(userName){
   userName = parseInt(userName);
   userName = !isNaN(userName);
   return userName;
}

The function returns "true" when the value starts with number like: "200abcde" but doesn't return "true" value with if the numbers are between alpha or at the end. I know, this could be done easily with regular expression but I want to achieve this without regular expression.

Note: There are plenty of similar questions here but didn't work any of them to solve my case.

See the second part of [this SO answer](http://stackoverflow.com/a/5778071/2397327). — Jonathan Lam, Nov 13 '15 at 04:26
Use a regular expression. It's much easier. The alternative ends up with a lot more code. — slebetman, Nov 13 '15 at 04:30

score 1 · Accepted Answer · answered Nov 13 '15 at 04:30

If you don't want to use regular expressions, you can split your string into an array of characters and then check the characters to see if it at least one of them are a number by using the some() method.

function isNumeric(userName) { 
  return userName.split('').some(function(c) {
    return !isNaN(c); 
  });
}

Like other people have said, using a regular expression would be a much cleaner way of doing it.

JavaScript isNumeric function

1 Answers1