Javascript Useful Array Methods Part 1

Useful Array Methods - Part 1

Mutable array methods

Let’s first see the array methods that you should be careful before using, mutable array methods.

Array.pop() - It doesn’t take any parameters, removes the last element from an array and returns that element.

Array.push() - It adds one or elements to the end of an array.

Array.shift() - It removes first element from an array and returns that element.

Array.unshift() - Adds one or more elements to the start of an array and returns new length.

Array.reverse() - It reverses the array elements and returns reference to the same array.

Array.sort() - It sorts the array elements in ascending order by default, It converts the elements into strings and then sorts according to each character’s Unicode value.

Array.splice() - Changes array by removing or replacing elements and also add new elements. splice(start, deleteCount, elem1) . It returns array of only deleted/removed elements else if added new elements, then it returns an empty array.

let weekdays = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
weekdays.pop() // 'Sat'
weekdays.push('Sat') // 'Sat' , length: 7
weekdays.shift() // 'Sun'
weekdays.unshift('Sun') // 'Sun' , length: 7
weekdays.reverse() // [ 'Sat', 'Fri', 'Thu', 'Wed', 'Tue', 'Mon', 'Sun' ]
weekdays.sort() // [ 'Fri', 'Mon', 'Sat', 'Sun', 'Thu', 'Tue', 'Wed' ]
weekdays.splice(3,0,'Feb'); // [ 'Sun', 'Mon', 'Tue', 'Feb', 'Wed', 'Thu', 'Fri', 'Sat' ]