Add to the end of an Array

var newLength = fruits.push('Orange');
// ["Apple", "Banana", "Orange"]
Remove from the end of an Array

var last = fruits.pop(); // remove Orange (from the end)
// ["Apple", "Banana"];
Remove from the front of an Array

var first = fruits.shift(); // remove Apple from the front
// ["Banana"];
Add to the front of an Array

var newLength = fruits.unshift('Strawberry') // add to the front
// ["Strawberry", "Banana"];
Find the index of an item in the Array

fruits.push('Mango');
// ["Strawberry", "Banana", "Mango"]

var pos = fruits.indexOf('Banana');
// 1
Remove an item by index position

var removedItem = fruits.splice(pos, 1); // this is how to remove an item

// ["Strawberry", "Mango"]
Remove items from an index position

var vegetables = ['Cabbage', 'Turnip', 'Radish', 'Carrot'];
console.log(vegetables);
// ["Cabbage", "Turnip", "Radish", "Carrot"]

var pos = 1, n = 2;

var removedItems = vegetables.splice(pos, n);
// this is how to remove items, n defines the number of items to be removed,
// from that position(pos) onward to the end of array.

console.log(vegetables);
// ["Cabbage", "Carrot"] (the original array is changed)

console.log(removedItems);
// ["Turnip", "Radish"]
Copy an Array

var shallowCopy = fruits.slice(); // this is how to make a copy
// ["Strawberry", "Mango"]