This content originally appeared on DEV Community and was authored by MANIKANDAN
What is a method?
A method is just a function inside an object,
and it represents what the object can do.
Now we are going to see some of the most frequently used built-in methods in JavaScript
Array methods()
1) push()
–> It is used to add one or more elements to the end of an array.
–> It also returns the new length of the array.
Syntax
array.push(element1, element2, ...);
Example
let tasks = ["Wake up", "Brush teeth"];
tasks.push("Exercise", "Read a book");
console.log(tasks);
Output
["Wake up", "Brush teeth", "Exercise", "Read a book"]
2) pop()
–>pop() removes the last element from the array
–> It returns the removed element
Syntax
array.pop();
Example
let tasks = ["Wake up", "Brush teeth", "Exercise", "Read a book"];
let removedTask = tasks.pop();
console.log(tasks);
console.log("Removed:", removedTask);
Output
["Wake up", "Brush teeth", "Exercise"]
Removed: Read a book
3) shift()
–>shift() removes the first element from the array
–> It returns the removed element
Syntax
array.shift();
Example
let tasks = ["Wake up", "Brush teeth", "Exercise", "Read a book"];
let removedTask = tasks.shift();
console.log(tasks);
console.log("Removed:", removedTask);
Output
["Brush teeth", "Exercise", "Read a book"]
Removed: Wake up
4) unshift()
–>unshift() adds one or more elements to the beginning of the array
–> It returns the new length of the array
Syntax
array.unshift();
Example
let tasks = ["Brush teeth", "Exercise", "Read a book"];
let newLength = tasks.unshift("Wake up");
console.log(tasks);
console.log("New Length:", newLength);
Output
["Wake up", "Brush teeth", "Exercise", "Read a book"]
New Length: 4
5) map()
–> map() creates a new array
–> It runs a function on every element of the original array
–> It does NOT change the original array
Syntax
array.map(function(element, index, array) {
// return new value
});
Example
let numbers = [1, 2, 3, 4];
let doubled = numbers.map(function(num) {
return num * 2;
});
console.log(numbers);
console.log(doubled);
Output
[1, 2, 3, 4]
[2, 4, 6, 8]
This content originally appeared on DEV Community and was authored by MANIKANDAN