JavaScript Regex to remove text after a comma and the following word?

When working with strings in JavaScript, you might encounter scenarios where you need to clean or format text by removing specific portions. A common task is to remove text after a comma and the following word. This can be achieved efficiently using JavaScript Regular Expressions (Regex). In this article, we'll show you how to do it step-by-step.

Why Use Regex for Text Manipulation?

Regex, short for Regular Expressions, is a powerful tool for pattern matching and text processing. It allows you to identify and manipulate text patterns with precision, making tasks like cleaning data or reformatting strings much simpler.

How to Remove Text After a Comma and the Following Word?

To achieve this, we'll use a Regex pattern in JavaScript's replace() method. This pattern identifies the portion of text to be removed and replaces it with an empty string.

The Regex Pattern

The pattern we'll use is ?

, \w+.*$

Here's what each part means ?

• ,: Matches a literal comma.
• : Matches a space after the comma.
• \w+: Matches one or more word characters (letters, digits, or underscores).
• .*: Matches the rest of the line after the word.
• $: Ensures the match extends to the end of the string.
  

Using Match() Method 

In this approach, the match function is paired with regex capturing groups to isolate different parts of a string based on a defined pattern. Once the desired segments are extracted, additional string operations, such as splitting or concatenating, are performed to reassemble or modify the string.

• The match() method in JavaScript is a versatile tool for extracting specific patterns. 

Example

Below is an example that demonstrates how to remove text after a comma and the following word using the match() method ?

var sentence = 'My Name is John, Smith I live in US';
console.log("The original value="+sentence);
var expression = sentence.match(/([^,]*)(.*)/)[1];
var positionForComma = sentence.match(/([^,]*),(.*)/)[2].split(' ')[1]
var newValue = expression + ', ' + positionForComma
console.log("Updated="+newValue);

Output

The original value=My Name is John, Smith I live in US
Updated=My Name is John, Smith

Using Replace() Method

The second method relies on the replace function, combined with a regular expression, to directly substitute or remove unwanted parts of the string. This approach focuses on identifying the unwanted text and replacing it with nothing (or another string).

• replace() Method: Takes two arguments - the Regex pattern to match and the replacement string (in this case, an empty string).

Example

Below is an example that demonstrates how to remove text after a comma and the following word using the replace() method ?

//Original string
const input = "This is a test, remove this part";

//Use Regex to remove text after a comma and the following word
const result = input.replace(/, \w+.*$/, '');

//Output the result
console.log(result);

Output

This is a test

Comparison Table

Aspect	Match() Method	Replace() Method
Core Method	match and manual string manipulation.	replace for direct string substitution.
Complexity	Relatively more complex due to multiple operations.	Simpler, as it directly removes unwanted text.
Flexibility	Allows extracting and reassembling parts of the string.	Primarily suited for removing unwanted text.
Performance	May be slower due to additional string operations.	Faster as it uses a single operation.