trimStart() in JavaScript – Remove Whitespace from String's Beginning
Whenever you use trimStart() on a string, the method does the following:
- It trims whitespace at the start of the string.
- It returns the new version of the calling string—without changing the original string.
note
- A calling string is a string on which you used
trimStart()
. So, in" Hello, world! ".trimStart()
," Hello, world! "
is the calling string. - Whitespace means the space character, tab, carriage return, new line, form feed, vertical tab, and other Unicode whitespace characters.
trimLeft()
is an alias fortrimStart()
. So, you can technically use the two methods to trim whitespace at the start of a string. However, it's best practice to usetrimStart()
.trimStart()
is sometimes written asString.prototype.trimStart()
because it is a method of theString
object'sprototype
property.
Syntax of the trimStart()
Method
trimStart()
accepts no arguments. Here is the syntax:
callingString.trimStart();
Example: Use trimStart()
to Remove Whitespace at the Beginning of a String
const myColor = " I love blue. ";
// Remove whitespace characters at the beginning of myColor:
myColor.trimStart();
// The invocation above will return: "I love blue. "
Note that you can alternatively use replace()
and regular expression to implement trimStart()
's functionality.
Example: Use replace()
and Regular Expression to Remove Whitespace at the Beginning of a String
const myName = " My name is Oluwatobi. ";
// Trim away the whitespace at the beginning of myName:
trimStartWhitespace(myName);
function trimStartWhitespace(string) {
return string.replace(/^\s+/gm, "");
}
// The invocation above will return: "My name is Oluwatobi. "
tip
Overview
The JavaScript trimStart()
method trims whitespace only at the beginning of a string.