How to Find If an Array Contains a Specific String in JavaScript/jQuery?

Given an Array, the task is to check whether an array contains a specific string in JavaScript and jQuery.

1. Using Array includes() Method

The includes() method is one of the simplest ways to check if an array contains a specific string. It is designed to test for the presence of an element in an array.

let arr1 = [10, 20, 30, 40, 50];

console.log(arr1.includes(30)); // Output: true
console.log(arr1.includes(70));  // Output: false

let arr2 = ["HTML", "CSS", "JavaScript", "React"];
console.log(arr2.includes("CSS")); // Output: true
console.log(arr2.includes("PHP"));  // Output: false

2. Using Array indexOf() Method

The indexOf() method returns the index of the first occurrence of a value in an array or -1 if the value is not found.

let arr1 = [10, 20, 30, 40, 50];

console.log(arr1.indexOf(30) !== -1); // Output: true
console.log(arr1.indexOf(70) !== -1);  // Output: false

let arr2 = ["HTML", "CSS", "JavaScript", "React"];
console.log(arr2.indexOf("CSS") !== -1); // Output: true
console.log(arr2.indexOf("PHP") !== -1);  // Output: false

3. Using Array some() Method

The some() method is useful for checking if at least one element in an array meets a specific condition. This method is particularly effective for arrays of objects or for applying custom logic.

let arr1 = [10, 20, 30, 40, 50];
let containsNum = arr1.some(item => item === 30);
console.log(containsNum); // Output: true
containsNum = arr1.some(item => item === 70);
console.log(containsNum); // Output: false


let arr2 = ["HTML", "CSS", "JavaScript", "React"];
let containsStr = arr2.some(item => item === "CSS");
console.log(containsStr); // Output: true
containsStr = arr2.some(item => item === "PHP");
console.log(containsStr); // Output: false

4. Using Regular Expressions

Regular expressions (RegExp) can be used to check for partial matches or to ignore case sensitivity.

// Applied on Numer Array
let arr1 = [10, 20, 30, 40, 50];
let regex = /30/i; // Case-insensitive match
let containsNum = arr1.some(item => regex.test(item));
console.log(containsNum); // Output: true

regex = /70/i;
containsNum = arr1.some(item => regex.test(item));
console.log(containsNum); // Output: false

// Applied on String Array
let arr2 = ["HTML", "CSS", "JavaScript", "React"];
regex = /CSS/i; // Case-insensitive match
let containsStr = arr2.some(item => regex.test(item));
console.log(containsStr); // Output: true

regex = /PHP/i;
containsStr = arr2.some(item => item === "PHP");
console.log(containsStr); // Output: false */

5. Using jQuery.inArray() Method

If you’re using jQuery, the $.inArray() function checks whether a value exists in an array.

let arr1 = [10, 20, 30, 40, 50];

console.log($.inArray(30, arr1) !== -1); // Output: true
console.log($.inArray(70, arr1) !== -1);  // Output: false

let arr2 = ["HTML", "CSS", "JavaScript", "React"];
console.log($.inArray("CSS", arr2) !== -1); // Output: true
console.log($.inArray("PHP", arr2) !== -1);  // Output: false

6. Using Lodash’s _.includes() Method

If you’re using Lodash, the _.includes() function simplifies the process of checking for the existence of a value.

let arr1 = [10, 20, 30, 40, 50];
console.log(_.includes(arr1, 30)); // Output: true
console.log(_.includes(arr1, 70));  // Output: false

let arr2 = ["HTML", "CSS", "JavaScript", "React"];
console.log(_.includes(arr2, "CSS")); // Output: true
console.log(_.includes(arr2, "PHP"));  // Output: false