How to split a string into an array of substrings in JavaScript?

If you want to split a string into an array of substrings, then JavaScript provides you the String.prototype.split() method. The split() method accepts two optional arguments, separator, and limit.

The syntax for the split() method is:

let substringsArray = str.split(separator, limit);

The separator is used to specify the condition based on which the string will be split. The separator can be a string or regular expression.

If you don't pass the separator, then the split() method returns the entire string.

The limit> is used to specify the number of substrings that will be returned by the split() method. The limit is an optional argument, and it could be a zero or positive number.

JavaScript String split() Examples

Let's understand how to use the split() method by going through some examples.

How to split a string into words?

When you want to split a string into words then a space character is used as a separator.

let str = 'I am learning JavaScript';

console.log(str.split(" "));

Output

["I", "am", "learning", "JavaScript"]

How to split a string into an array of characters?

If you want to split a word into letters, then pass an empty string as a separator to the split() method.

let str = 'JavaScript';

console.log(str.split(""));

Output

["J", "a", "v", "a", "S", "c", "r", "i", "p", "t"]

How to limit the number of substrings returned by the split() method?

The following example passes 3 to the limit argument. By doing this, the number of substrings will be limited to three.

let str = 'I am learning JavaScript';

console.log(str.split(" ", 3));

Output

["I", "am", "learning"]

How to split a string using regular expression?

It is important for you to know that you can pass a regular expression as a separator to the split() method.

The following example splits the paragraph into sentences:

let str = 'Hello Mohit! How are you?';

console.log(str.split(/[!?]/));

Output

["Hello Mohit", " How are you", ""]

If you want to include the characters based on which the string is split then surround that regular expression with a pair of parenthesis.

let str = 'Hello Mohit! How are you?';

console.log(str.split(/([!?])/));

Output

["Hello Mohit", "!", " How are you", "?", ""]