how to transform a string into a number code example
Example 1: javascript convert string to number or integer
//It accepts two arguments.
//The first argument is the string to convert.
//The second argument is called the radix. This is the base number used in mathematical systems. For our use, it should always be 10.
var text = '42px';
var integer = parseInt(text, 10);
// returns 42
Example 2: convert a string to number in javascript
var x = parseInt("1000", 10); // you want to use radix 10
// so you get a decimal number even with a leading 0 and an old browser ([IE8, Firefox 20, Chrome 22 and older][1])