Javascript String includes()

const message = "JavaScript is fun";

// check if message includes the string "Java"
let result = message.includes("Java");
console.log(result);

// Output: true

includes() Syntax

The syntax of the includes() method is:

str.includes(searchString, position)

Here, str is a string.

includes() Parameters

The includes() method takes in:

• searchString - A string to be searched for within str.
• position (optional) - The position within str to begin searching for searchString. By default, it is 0.

includes() Return Value

• Returns true if searchString is found anywhere within str.
• Returns false if searchString is not found anywhere within str.

Note: The includes() method is case sensitive.

Example: Using includes() method

let sentence = "Java is to JavaScript what Car is to Carpet.";

let check = sentence.includes("Java");
console.log(check); // true

// case sensitive
let check1 = sentence.includes("java");
console.log(check1); // false

// second argument specifies position to start at
let check2 = sentence.includes("Java", 20);
console.log(check2); // false

let check3 = sentence.includes("whose");
console.log(check3); // false

let check4 = sentence.includes("");
console.log(check4); // true

Output

true
false
false
false
true

Recommended Reading: JavaScript String indexOf()