The RegExp \b Metacharacter in JavaScript is used to find a match at the beginning or end of a word. If match is found it returns the word else it returns NULL.
Syntax:
/\b/
or
new RegExp("\\b")
Syntax with modifiers:
/\b/g
or
new RegExp("\\b", "g")
Example 1: This example matches the word “GeeksforGeeks” at the beginning of the string.
<!DOCTYPE html> < html > < head > < title > JavaScript RegExp \b Metacharacter </ title > </ head > < body style = "text-align:center" > < h1 style = "color:green" > GeeksforGeeks </ h1 > < h2 >RegExp \b Metacharacter</ h2 > < p >Input String: GeeksforGeeks@_123_$</ p > < button onclick = "geek()" > Click it! </ button > < p id = "app" ></ p > < script > function geek() { var str1 = "GeeksforGeeks@_123_$"; var regex4 = /\bgeeksforgeeks/gi; var match4 = str1.match(regex4); document.getElementById("app").innerHTML = "Found " + match4.length + " match: " + match4; } </ script > </ body > </ html > |
Output:
Before Clicking the button:
After Clicking the button:
Example 2: This example matches the word “Geeky” at the beginning and replaces it with the word “GFG”.
<!DOCTYPE html> < html > < head > < title > JavaScript RegExp \b Metacharacter </ title > </ head > < body style = "text-align:center" > < h1 style = "color:green" > GeeksforGeeks </ h1 > < h2 >RegExp \b Metacharacter</ h2 > < p >String: Geeky@128</ p > < button onclick = "geek()" > Click it! </ button > < p id = "app" ></ p > < script > function geek() { var str1 = "Geeky@128"; var regex4 = new RegExp("\\bGeeky", "gi"); var replace = "GFG"; var match4 = str1.replace(regex4, replace); document.getElementById("app").innerHTML = " New string: " + match4; } </ script > </ body > </ html > |
Output:
Before Clicking the button:
After Clicking the button:
Supported Browsers: The browsers supported by RegExp \b Metacharacter are listed below:
- Google Chrome
- Apple Safari
- Mozilla Firefox
- Opera
- Internet Explorer