array.js

/* eslint-disable */

// see: book/chapters/array.adoc

const array = [2, 5, 1, 9, 6, 7]; // JavaScript
array[4]; //=> 6

// Insert to tail
array.push(4); // array: [2, 5, 1, 9, 6, 7, 4]

// Insert/update values anywhere
array[8] = 3; // array: [2, 5, 1, 9, 6, 7, 4, empty, 3]

// Insert to head, changes every index
array.unshift(0); // array: [0, 2, 5, 1, 9, 6, 7, 4, empty, 3];

// Deleting could change all the indexes
// on the position 4, delete 2 elements
array.splice(4, 2); // array: [0, 2, 5, 1, 7, 4, empty, 3]

// Inserting element sin the middle
array.splice(1, 0, 111); // at the postion 1, delete 0 elements and insert 111
//=> array: [2, 111, 5, 1, 9, 6, 7]

// Deleting from the beginning of the array.
array.shift(); //=> [5, 1, 9, 6, 7]

// Deleting from the middle
array.splice(2, 1); // delete 1 element at position 2
// => array: [2, 5, 9, 6, 7]

// Deleting last element from the array
array.pop(); // => array: [2, 5, 1, 9, 6]