How to compare two regexps?

Try this:

String(regexp1) === String(regexp2))

You are getting false because those two are different objects.

"Problem":

regex is an object- a reference type, so the comparsion is done by reference, and those are two different objects.

console.log(typeof /a/); // "object"

If both operands are objects, then JavaScript compares internal references which are equal when operands refer to the same object in memory.

MDN

Solution:

​var a = /a/;
var b = /a/;
console.log(​​​a.toString() === b.toString()); // true! yessss!

Live DEMO

Another "hack" to force the toString() on the regexes is:

console.log(a + "" === b + "");​

Just a guess - but doesn't JavaScript create a RegExp object for your regex, and therefore because you have created two different objects (even though they have the same "value") they're actually different?