JavaScript - String Strip

Here are the different methods to Strip String in JavaScript

Using trim() Method (Most Common)

The trim() method removes whitespace from both ends of a string. This is the most commonly used to strip whitespace in JavaScript.

const s1 = "   Hello, World!   ";
const s2 = s1.trim();
console.log(s2); 

Hello, World!

• Removes only leading and trailing whitespace.
• Does not alter whitespace within the string.

Using replace() Method

The replace() method, combined with regular expressions, provides more flexibility. You can remove specific patterns like leading, trailing, or all whitespace.

Remove Leading and Trailing Whitespace

const s1 = "   Hello, World!   ";
const s2 = s1.replace(/^\s+|\s+$/g, "");
console.log(s2); 

Hello, World!

• ^\s+: Matches leading whitespace.
• \s+$: Matches trailing whitespace.
• |: Combines both conditions.

Remove All Whitespace

const s1 = "   Hello,    World!   ";
const s2 = s1.replace(/\s+/g, "");
console.log(s2); 

Hello,World!

• \s+: Matches all whitespace (spaces, tabs, newlines).

Using Lodash’s _.trim() Method

If you’re already using Lodash, the _.trim() method simplifies string stripping, supporting additional characters for trimming.

const _ = require("lodash");
const s = "   Hello, World!   ";
const stripped = _.trim(s);
console.log(stripped);

Output

Hello, World!

• Trims leading and trailing whitespace by default.
• Supports custom characters for trimming.

Using Manual Looping

If you prefer a manual approach or need complete control, you can loop through the string to strip whitespace.

const s1 = "   Hello, World!   ";
let start = 0;
let end = s1.length - 1;

while (s1[start] === " ") start++;
while (s1[end] === " ") end--;

const s2 = s1.slice(start, end + 1);
console.log(s2);

Hello, World!

• The while loops increment start and decrement end until non-whitespace characters are found.
• slice(start, end + 1) extracts the trimmed substring.

Using String.trimStart() and String.trimEnd() - Modern Approach

Modern JavaScript provides trimStart() and trimEnd() methods for specific whitespace removal.

const s = "   Hello, World!   ";
console.log(s.trimStart());
console.log(s.trimEnd());   

Hello, World!   
   Hello, World!

• Use trimStart() to remove leading whitespace.
• Use trimEnd() to remove trailing whitespace.

Comparison of Methods