Table of contents
No headings in the article.
Arrays in javascript are the most commonly used data structure for manipulating and storing data. Arrays allow you to do a lot of things and make the life of a developer much easier. For beginners, here are some array methods to try :
`push()`
This method allows you to push an element to the end of an array. Here's an example of the push method:
const arr = [1, 2, 3]; arr.push(10); console.log(arr); // [ 1, 2, 3, 10 ]
`pop()`
This method removes an element from the end of an array. Here is an example of the pop method.
const arr = [1, 2, 3]; arr.pop(); console.log(arr); // [ 1, 2 ]
`shift()`
The pop method removes an item from the end of an array. However, the shift method removes the item from the beginning of the array.
const arr = [1, 2, 3]; arr.shift(); console.log(arr); // [ 2, 3 ]
`unshift()`
The unshift method is used for adding items in the same way that the push method is. However, it places the item at the beginning of the array.
const arr = [1, 2, 3]; arr.unshift(0); console.log(arr); // [ 0, 1, 2, 3 ]
`slice()`
Unlike the previous four methods, it returns a new array. The syntax is :
arr.slice(start, end)
It returns an array from the start index item to the end index item. Please keep in mind that it does not return the end index item. For instance :
const arr = [1, 2, 3, 4, 5]; const newArr = arr.slice(0, 2); console.log(newArr); // [ 1, 2 ]
If you do not add the end index. It will take all items from the first index.
const arr = [1, 2, 3, 4, 5]; const newArr = arr.slice(2); console.log(newArr); // [ 3, 4, 5 ]
You can also use negative index values. For instance :
const arr = [1, 2, 3, 4, 5]; const newArr = arr.slice(-1); // It will return the last index value console.log(newArr); // [ 5 ]
`splice()`
This method does not return a new array. It modifies the original array. Here's a syntax :
arr.splice(start, delete, [item1, item2, ..., itemN])
This method is a little confusing. So let's look at an example. This is a simple example of deleting values.
let arr = ["HTML", "CSS", "JavaScript", "React"]; arr.splice(1, 2); // from index 1 remove 2 elements console.log(arr); // [ 'HTML', 'React' ]
Let's take a more complex example :
let arr = ["HTML", "CSS", "JavaScript", "React"]; arr.splice(1, 2, "PHP", "C++"); // from index 1 remove 2 elements and add "PHP", "C++" instead of them console.log(arr); // [ 'HTML', 'PHP', 'C++', 'React' ]
There are still many methods available. I'll post them soon.