Modifiers for regex strings in JavaScript

Modifiers in regexes created with RegExp should be passed as the second parameter. Let's look at an example. Let's say we have the following string:

let str = 'abc def';

Let's apply the following regular expression with a modifier to this string:

let reg = /[a-z]+/g;
let res = str.match(reg);

Let's rewrite this regular expression using RegExp:

let reg = new RegExp('[a-z]+', 'g');
let res = str.match(reg);

Practical tasks

Rewrite a regular expression as a string:

let str = '123 456 789';
let reg = /[0-9]+/g;
let res = str.replace(reg, '!');