I need a help for regexp in javascript code

Question

var str = "^" + "/post/\d+" + "$";
var regex = new RegExp(str);
var flag = regex.test("/post/3333");

console.log(flag) // -> false
console.log(regex) // -> /^\/post\/d+$/

I'm expecting the result becomes true, but it results in false.

I think the problem is "\\" is added automatically before "/" when RegExp instance is created.

How am I supposed to write in order to make it work?

Answer 1

You don't need the new RegExp constructor and string Here example

var regex = /post\/\d+$/;
var flag = regex.test("/post/3333");

I removed ^ flag, because regex will not work with this format of input "website/post/3333"

Answer 2

Here's a more specific regular expression to match the format of /post/#### :

var regex = /\/post\/[0-9]+$/;
var flag = regex.test("/post/3333");

This will test for the string /post/ followed by one or more digits, occurring at the end of the line.

Likewise:

var regex = /\/post\/[0-9]{4}$/;
var flag = regex.test("/post/3333");

will test for the string /post/ followed by 4 digits, occurring at the end of the line.