string to regex javascript code example

Example 1: js string to regex

const regex = new RegExp('https:\\/\\/\\w*\\.\\w*.*', 'g');

Example 2: js match any number string

const match = 'some/path/123'.match(/\/(\d+)/)
const id = match[1] // '123'

Example 3: using regex in javascript

//Adding '/' around regex
var regex = /\s/g;
//or using RegExp
var regex = new RegExp("\s", "g");

Example 4: how to use the match function in javascript for regex

const str = 'For more information, see Chapter 3.4.5.1';
const re = /see (chapter \d+(\.\d)*)/i;
const found = str.match(re);

console.log(found);

// logs [ 'see Chapter 3.4.5.1',
//        'Chapter 3.4.5.1',
//        '.1',
//        index: 22,
//        input: 'For more information, see Chapter 3.4.5.1' ]

// 'see Chapter 3.4.5.1' is the whole match.
// 'Chapter 3.4.5.1' was captured by '(chapter \d+(\.\d)*)'.
// '.1' was the last value captured by '(\.\d)'.
// The 'index' property (22) is the zero-based index of the whole match.
// The 'input' property is the original string that was parsed.

Example 5: regex for strings with specific letters javascript

let re = /ab+c/;

Example 6: regular expression javascript

// Tests website Regular Expression against document.location (current page url)
if (/^https\:\/\/example\.com\/$/.exec(document.location)){
	console.log("Look mam, I can regex!");
}