Deep Copy of an Array (and Object -> Method 4)

deep_copy_of_an_js_array.js

// METHODE 1

Array.prototype.slice.call([array])

/*
 * Example
 var arr = [37, 1, 2, 3],
     arr2 = Array.prototype.slice.call(arr);
     
  console.log(arr === arr2); // false => not equal
 */


// METHODE 2: Prototype:
Array.prototype.deepCopy = function() {
  return Array.prototype.slice.call(this);
};
/*
 * Example
 var arr = [37, 1, 2, 3],
     arr2 = arr.deepCopy;
     
  console.log(arr === arr2); // false => not equal
 */


// METHODE 3: Spread Operator (ES2015)
var arr = [1, 2, 3],
    arr2 = [...arr];

arr === arr2; // => false


// METHODE 4: JSON.stringify/JSON.parse
var arr = [{ x:{z:1} , y: 2}],
    arr2 = JSON.parse(JSON.stringify(arr));

arr === arr2; // => false

// prototype
Array.prototype.copy = function() {
    return JSON.parse(JSON.stringify(arr));
}