How can I check if a string is a float?

Question

I am passing in a parameter called value. I\'d like to know if value is a float. So far, I have the following:

if (!isNaN(value))
{
    alert(\'this is a num         


        

Answer 1

You can use the parseFloat function.

If the value passed begins with what looks like a float, the function returns the value converted to a float, otherwise it will return NaN.

Something like:

function beginsWithFloat(val) {
  val = parseFloat(val);
  return ! isNaN(val);
}
console.log(beginsWithFloat("blabla")); // shows false
console.log(beginsWithFloat("123blabla")); // shows true