typescript map array

var numbers = [4, 9, 16, 25];
var x = numbers.map(Math.sqrt)

document.getElementById("demo").innerHTML = x; 

const array1 = [1, 4, 9, 16];

var map1 = array1.map(x => x * 2);
var map2 = array1.map( function( x, i ) {
  	console.log(x, i);
  	// x = 1 , 4 , 9 ,16 i = 0 , 1 , 2 , 3
    return x
} ); 
console.log(map1);
// expected output: Array [2, 8, 18, 32]