convert string to value javascript code example

Example 1: how to change a string to number in javascript

let theInt = parseInt("5.90123"); //5
let theFloat = parseFloat("5.90123"); //5.90123

Example 2: string to int javascript

var text = '42px';
var integer = parseInt(text, 10);
// returns 42

Example 3: javascript string to a decimal

<script language="JavaScript" type="text/javascript">
var a = "3.3445";
var c = parseFloat(a);
alert(c);
</script>

Example 4: string to number javascript

new Number(valeur);
var a = new Number('123'); // a === 123 donnera false
var b = Number('123'); // b === 123 donnera true
a instanceof Number; // donnera true
b instanceof Number; // donnera false