string to int javascript

let string = "1";
let num = parseInt(string);
//num will equal 1 as a intvar myInt = parseInt("10.256"); //10
var myFloat = parseFloat("10.256"); //10.256var text = '42px';
var integer = parseInt(text, 10);
// returns 42
let myNumber = Number("5.25"); //5.25var text = '42px';
var integer = parseInt(text, 10);
// returns 42
var text = '3.14someRandomStuff';
var pointNum = parseFloat(text);
// returns 3.14
// Convert strings
Number('123'); // returns 123
Number('12.3'); // returns 12.3
Number('3.14someRandomStuff'); // returns NaN
Number('42px'); // returns NaN