String.prototype.trim()

Summary: in this tutorial, you’ll learn how to use the JavaScript trim() method to remove whitespace characters from both ends of a string.

Introduction to the JavaScript trim() method

The String.prototype.trim() returns a new string with whitespace trimmed from the beginning and end of a string.

Here’s how to use the trim() method:

let newString = str.trim();Code language: JavaScript (javascript)

Note that the trim() method returns a completely new string and doesn’t change the original string.

In JavaScript, the following characters are whitespace:

• A space character (' ')
• A tab character (\t)
• A carriage return character (\r)
• A new line character. (\n)
• A vertical tab character. (\v)
• A form feed character. (\f )

To remove whitespace characters from the beginning or the end of a string only, you use the trimStart() or trimEnd() method.

JavaScript trim() method examples

Let’s take some examples of using the trim() method.

Basic JavaScript trim() examples

The following example shows how to use the trim() to remove whitespace from both sides of a string:

let str = '  JavaScript trim  ';
let result = str.trim();

console.log({str});
console.log({result});Code language: JavaScript (javascript)

Output:

{str: '  JavaScript trim  '}
{result: 'JavaScript trim'}Code language: JavaScript (javascript)

The following example illustrates how to use the trim() method to remove the leading and trailing newlines from a string:

let str = '\nJavaScript Tutorial\n\n';
let result = str.trim();

console.log({str});
console.log({result});Code language: JavaScript (javascript)

Output:

{str: '\nJavaScript Tutorial\n\n'}
{result: 'JavaScript Tutorial'}Code language: CSS (css)

Chaining with other string methods

Since the trim() method returns a string, you can chain it with other string methods. For example:

let name = '  John Doe ';
let [firstName, lastName ] = name.trim().split(' ');

console.log({firstName, lastName});Code language: JavaScript (javascript)

Output:

{firstName: 'John', lastName: 'Doe'}Code language: JavaScript (javascript)

In this example, we use the trim() method to remove the leading and trailing whitespace from a string and then use the split() method to split the string into two parts.

Summary

• Use the trim() to remove whitespace characters from both ends of a string.