Question

Those two regex act the same way:

var str = "43gf\\..--.65";

console.log(str.replace(/[^\d.-]/g, ""));
console.log(str.replace(/[^\d\.-]/g, ""));

In the first regex I don’t escape the dot(.) while in the second regex I do(\.).

What are the differences? Why is the result the same?

Answer 1

Because the dot is inside character class (square brackets []).

Take a look at http://www.regular-expressions.info/reference.html, it says (under char class section):

Any character except ^-]\ add that character to the possible matches
for the character class.