Remove a specific element from an array in JavaScript

This post will discuss how to remove a specific element from an array in JavaScript.

There are several ways to remove a specific element from an array, depending on the index and the value of the element we want to remove. Here are some examples in JavaScript given an array and an element:

1. Using `indexOf()` and `splice()` functions

These functions allow us to find the index of the element we want to remove using indexOf(), and then remove that element using Array.splice(). The splice() function changes the contents of an array by removing existing elements and/or adding new elements. For example, if we have an array [1, 2, 3, 4, 5] and we want to remove the element 3, we can do:

let arr = [1, 2, 3, 4, 5]; // original array

let element = 3; // the element to remove

// remove the element from the copy

arr.splice(arr.indexOf(element), 1);

console.log(arr); // [1, 2, 4, 5]

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If the element is not found in the array, the indexOf() function returns -1 and splice function call translates to arr.splice(-1, 1). Since negative index counts back from the end of the array, this will remove the last element from the array. To avoid this unwanted output, it is recommended to call splice() function only when the element is found in the array. For example, we can use something like this:

let arr = [1, 2, 3, 4, 5]; // original array

let element = 3; // the element to remove

// find the index of the element

let index = arr.indexOf(element);

// call splice only when the element is found in the array

if (index > -1) {

// remove one element at the index

arr.splice(index, 1);

}

console.log(arr); // [1, 2, 4, 5]

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2. Using `filter()` function

The filter() function allows us to create a new array with all elements that pass a test implemented by a provided function. We can use it to filter out the element we want to remove from the original array. This will return a new array that contains all elements except the specified element. For example, if we have an array [1, 2, 3, 4, 5] and we want to remove the element 3, we can do like below. Based on the type of array, we can use the strict equality operator (===) in the callback function, or perform some custom comparison.

let arr = [1, 2, 3, 4, 5]; // original array

let element = 3; // the element to remove

let newArr = arr.filter(function(item) {

// return true for all elements except the one to remove

return item !== element;

});

console.log(newArr); // [1, 2, 4, 5]

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3. Using a for loop

This function allows us to iterate over the array and check each element for equality with the element we want to remove. To use it, we need to declare a variable that stores a new empty array. Then, we need to loop over the original array and push every element that is not equal to the specified element into the new array. We can then assign the original array to the new array or return it as a result. For instance:

function removeItem(arr, element) {

// Declare a new empty array

let newArr = [];

// Loop over the original array

for (let i = 0; i < arr.length; i++) {

// If the current element is not equal to the specified element

if (arr[i] !== element) {

// Push it into the new array

newArr.push(arr[i]);

}

return newArr;

}

let arr = [1, 2, 3, 4, 5]; // original array

let element = 3; // the element to remove

let newArray = removeItem(arr, element);

console.log(newArray); // [1, 2, 4, 5]

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That’s all about removing a specific element from an array in JavaScript.

Remove a specific element from an array in JavaScript

1. Using indexOf() and splice() functions

2. Using filter() function

3. Using a for loop

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1. Using `indexOf()` and `splice()` functions

2. Using `filter()` function