I'm currently making a simple calculator for use in an intro to Javascript lesson. I would like to know if there's a simpler way of taking the value from a HTML input textbox as an integer than having to use the Javascript parse() method?
HTML:
<input type = "Text" id="num1">
JS:
var num1 = parseInt(document.getElementById("num1").value);
You can force a string to be a 32-bit integer like this:
var num1 = ~~document.getElementById("num1").value;
You can, alternatively, accept a number with a possible fractional part with
var num1 = +document.getElementById("num1").value;
In both cases, you can check to see if the original string really did look like a number by using isNaN():
if (isNaN(num1)) {
// bad input
}
+document.getElementById("num1").value