Definition and Usage

The split() function splits a given string based on a specified delimiter or a regular expression and returns a new array.

This function is useful for processing strings that are split according to specific rules, such as parsing URLs.

Features

  • The string is split, and each part becomes an element in the resulting array.
  • Because this function returns a new array, the original string is not modified.

Basic Example

JavaScript 
/* Splitting a string using a specific delimiter */
const sentence = "JavaScript is a client-side scripting language.";
const wordsArray = sentence.split(" "); // Split the string into an array based on spaces

console.log(wordsArray);
// Output: ["JavaScript", "is", "a", "client-side", "scripting", "language."]


/* Splitting a string using a regular expression */
const str = "This is an example.";
const words = str.split(/\s+/); // Split the string into an array using a whitespace regular expression (/\s+/)

console.log(words[0]); // Output: "This"
console.log(words[1]); // Output: "is"
console.log(words[2]); // Output: "an"
console.log(words[3]); // Output: "example."


/* Parsing a URL */
const url = "https://www.example.com/path/to/file.html?param=value";

const parts = url.split("?"); // Split the URL into an array using "?" as the delimiter

console.log(parts[0]); // Output: "https://www.example.com/path/to/file.html"
console.log(parts[1]); // Output: "param=value"

Syntax

JavaScript 
str.split()
str.split(separator)
str.split(separator, limit)

str is the string to which the split() function is applied.

Parameters

Parameters of the split() Function
separator Optional.
The delimiter used to split the string. This can be specified as a string or a regular expression.
limit Optional.
An integer that specifies the maximum length of the array created when the string is split.
If omitted, the string is split using all occurrences of the separator.
Any remaining parts of the string beyond the specified limit are not included in the returned array.

Return Value

The function returns an array containing the parts of the string that were split based on the specified separator.

Example with Parameters and Return Values

When no parameters are provided

If no separator is specified, the returned array contains the original string as its only element.

JavaScript 
const sentence = "Hello. Welcome!";
const wordsArray = sentence.split();

console.log(wordsArray);
// Output: ["Hello. Welcome!"]
When an empty string ("") is specified as the separator

If the separator is an empty string (""), the returned array contains each character of the original string as an element.

JavaScript 
const sentence = "Hello. Welcome!";
const wordsArray = sentence.split("");

console.log(wordsArray);
// Output: ["H", "e", "l", "l", "o", ".", " ", "W", "e", "l", "c", "o", "m", "e", "!"]
When the separator appears at the beginning or end of the original string

If the specified separator appears at the beginning or end of the original string, the returned array also starts or ends with an empty string ("").

JavaScript When the separator appears at the beginning of the original string 
const sentence = ",Hello. Welcome!";

// Use "," as the separator at the beginning of the string
const wordsArray = sentence.split(",");

// The returned array starts with an empty string ("")
console.log(wordsArray);
// Output: ["", "Hello. Welcome!"]
JavaScript When the separator appears at the end of the original string 
const sentence = "Hello. Welcome!,";

// Use "," as the separator at the end of the string
const wordsArray = sentence.split(",");

// The returned array ends with an empty string ("")
console.log(wordsArray);
// Output: ["Hello. Welcome!", ""]
JavaScript When the separator appears at both the beginning and end of the original string 
const sentence = ",Hello. Welcome!,";

// Use "," as the separator at both the beginning and end of the string
const wordsArray = sentence.split(",");

// The returned array starts and ends with an empty string ("")
console.log(wordsArray);
// Output: ["", "Hello. Welcome!", ""]
When the separator is the same as the original string

If the separator is identical to the original string, the returned array contains two empty strings ("").

JavaScript 
const sentence = "H";
const wordsArray = sentence.split("H");

console.log(wordsArray);
// Output: ["", ""]
When both the separator and the original string are empty strings ("")

If both the separator and the original string are empty strings (""), an empty array is returned.

JavaScript 
const sentence = "";
const wordsArray = sentence.split("");

console.log(wordsArray);
// Output: []

Practical Examples

The split() function can be used effectively in a wide range of situations. This section covers several practical examples.

Splitting a String into Words

JavaScript 
const str = "This is an example.";
const words = str.split(" ");

console.log(words);
// Output: ["This", "is", "an", "example."]

Parsing a String

JavaScript 
const time = "02:30:45";
const timeParts = time.split(":");
const hours = timeParts[0];

console.log("Hours:", hours);
// Output: "Hours: 02"

Extracting a File Name from a File Path

JavaScript 
const filePath = "/path/to/file.txt";

/* Split by "/" and return the last element of the array using the pop() function */
const fileName = filePath.split("/").pop();

console.log(fileName);
// Output: "file.txt"

Additional Explanation
The pop() function removes the last element from an array and returns it.

Extracting a Domain from an Email Address

JavaScript 
const email = "user@example.com";
const parts = email.split("@");

const domain = parts[1];

console.log(domain);
// Output: "example.com"

Compatibility

Compatibility for JavaScript split() Function
Method
Desktop Chrome
Chrome
DesktopDesktop Edge
Edge
Desktop Firefox
Firefox
Safari
Safari
Node.js
Node.js
split() 1 12 1 1 0.10

Specifications

Specification for JavaScript split() Function
Specification
split() ECMAScript® 2026 Language Specification
#sec-string.prototype.split

References

See also