How to Use Regular Expressions to Match Whole Words in JavaScript?

How to Match a Specific Word Using Regular Expressions in JavaScript

In JavaScript, searching for a whole word within a string can be achieved with regular expressions. Here's a step-by-step guide on how to implement this functionality:

Step 1: Define the Regular Expression Pattern

To match a whole word, you can use the following regular expression pattern:

\b(pattern)\b

where pattern represents the word you want to search for and b is a word boundary anchor that ensures the search matches the beginning or end of the word.

Step 2: Creating a Dynamic Regular Expression

If the word you want to match is user-defined, you can create a dynamic regular expression using JavaScript's RegExp object:

new RegExp("\b" + lookup + "\b")

Step 3: Perform the Search

Once you have the dynamic regular expression, you can use the test() method on the regular expression object to perform the search:

new RegExp("\b" + lookup + "\b").test(textbox.value)

where textbox.value is the string in which you want to search.

Example

Consider the following example:

var lookup = '\n\n\n\n\n\n2    PC Games        \n\n\n\n';
lookup = lookup.trim();
var tttt = 'tttt';
alert((new RegExp("\b" + lookup + "\b")).test(2)); // true

This example searches for the word "lookup" in the lookup string and returns true because the word is found.

Important Note

Remember to use the correct direction when testing the regular expression. In the example above, the test is written as:

alert((new RegExp("\b" + lookup + "\b")).test(2));

instead of:

alert((new RegExp("\b" + lookup + "\b")).test(lookup));

which would incorrectly search for the word "2" within the lookup string.

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