I want a regex which returns true when there is at least 5 characters et 2 digits. For that, I use a the lookahead (i. e. (?=...)).
// this one works
let pwRegex = /(?=.{5,})(?=\D*\d{2})/;
let result = pwRegex.test("bana12");
console.log("result", result) // true
// this one won't
pwRegex = /(?=.{5,})(?=\d{2})/;
result = pwRegex.test("bana12");
console.log("result", result) // falseWhy we need to add \D* to make it work ?
For me, \d{2} is looser than \D*\d{2} so it should not allow an acceptance of the test?
Your lookaheads only test from the current match position. Since you don't match anything, this means from the start. Since bana12 doesn't start with two digits, \d{2} fails. Its as simple as that ;)
Also, note that having \d{2} means your digits has to be adjacent. Is that your intention?
To simply require 2 digits, that doesn't need to be adjacent, try
/(?=.{5,})(?=\D*\d\D*\d)/
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