string to number javascript

// Method - 1 ### parseInt() ###
var text = "42px";
var integer = parseInt(text, 10);
// returns 42

// Method - 2 ### parseFloat() ###
var text = "3.14someRandomStuff";
var pointNum = parseFloat(text);
// returns 3.14

// Method - 3 ### Number() ###
Number("123"); // returns 123
Number("12.3"); // returns 12.3
Number("3.14someRandomStuff"); // returns NaN
Number("42px"); // returns NaNlet string = "1";
let num = parseInt(string);
//num will equal 1 as a intvar myInt = parseInt("10.256"); //10
var myFloat = parseFloat("10.256"); //10.256parseInt(value);

let string = "321"
console.log(string); // "321" <= string

let number = parseInt(string);
console.log(number) // 321 <=intvar myString = "869.99"
var myFloat = parseFloat(myString)
var myInt = parseInt(myString)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