In JavaScript, the RegExp() constructor is used to create a RegExp object. This object can be created with or without the new keyword. The RegExp pattern can be passed in the constructor either in the literal notation or as a string. RegExp constructor is usually used when we want the p[attern to be decided dynamically.
Syntax:
RegExp(pattern, flag) new RegExp(pattern, flag)
Parameters: The constructor takes two parameters where the flag is optional
- pattern: This is the text to be matched or another RegExp object
- flag: It instructs which flags are to be checked when the match is performed
Return Value: A RegExp object which contains the pattern string
Example 1: This example creates a new RegExp object with literal and string notation.
Javascript
const reg1 = new RegExp(/ab/); const reg2 = new RegExp("ab"); console.log(reg1); console.log(reg1); |
Output:
/ab/ /ab/
Example 2: This example uses RegExp object to compare matching values in string.
Javascript
const str1 = "neveropen is a computer science platform" const reg1 = new RegExp(/[g]/,'g'); console.log(str1.match(reg1)); |
Output: It is an array containing matching characters.
(2)['g', 'g']
Supported Browsers:
- Chrome
- Edge
- Firefox
- Opera
- Safari
We have a complete list of Javascript RegExp expressions, to check those please go through this JavaScript RegExp Reference article.
