Javascript String includes()

The JavaScript String includes() method checks if one string can be found inside another string.

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.

Return value from includes()

  • 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()