how to multiply a variable with every value of an array in javascript?

Question

var numbers = [1, 5, 10, 15];
var doubles = numbers.map(function(x) {
  return x * 2;
  //doubles is now [2, 10, 20, 30]

I am following this above example, This is working for a constant 2, how can I mulitply the elements with variable this.price,

var numbers = [1, 5, 10, 15];
var doubles = numbers.map(function(x) {
   return x * this.price;

How can I make this works? this.price is a public variable.

Answer 1

var doubles = numbers.map(function(x) {
   return x * this.price; // "this" refers to the function it's inside
})

You can pass the external context inside the function using the ES6 fat arrow :

let doubles = numbers.map( x => x * this.price ) // "this" now refers to the parent's scope

Answer 2

var numbers = [1, 5, 10, 15];

var doubles = numbers.map(x => x * 5);

console.log(doubles);

Answer 3

simply use the loop for,foreach or while.

var numbers = [1, 5, 10, 15];
for (index = 0; index < numbers .length; ++index) {
    //your multiplication code goes here
}