Angular pattern validation with regex

Question

I need to make a password pattern validator

the password should have:

• 1 uppercase letter
• 1 lowercase letter
• A number
• A minimum length of 8.

I found this regex pattern:

Validators.pattern('/^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d!$%@#£€*?&]')

however, the validator always claims my input is invalid

errors:    
   pattern:
      actualValue: "Test1234"
      requiredPattern: "^/^(?=.*[A-Za-z])(?=.*d)[A-Za-zd!$%@#£€*?&]$"

according to https://regex101.com/r/AfAdKp/1 this value is supposed to be valid.

Edit: to clarify, Test1234 is supposed to work

Solution 1

You have multiple issues with your current regex:

1. Your regex doesn't have a quantifier for character class
2. Validators.pattern doesn't need delimiters but you threw one at beginning
3. You should double escape tokens.

What you need is this:

Validators.pattern('^(?=[^A-Z]*[A-Z])(?=[^a-z]*[a-z])(?=\\D*\\d)[A-Za-z\\d!$%@#£€*?&]{8,}$');

See live demo here

Solution 2

You have to add the quantifier [A-Za-z\d!$%@#£€*?&]{8,} to repeat the character class a minimum of 8 times and separate the assertions for an uppercase and lowercase character:

Validators.pattern('^(?=.*[A-Z])(?=.*[a-z])(?=.*\\d)[A-Za-z\\d!$%@#£€*?&]{8,}$')

^(?=.*[A-Z])(?=.*[a-z])(?=.*\d)[A-Za-z\d!$%@#£€*?&]{8,}$

• ^ Assert position at the start of the string
• (?=.*[A-Z]) Positive lookahead to assert that what follows is an uppercase character
• (?=.*[a-z]) Positive lookahead to assert that what follows is an lowercase character
• (?=.*\d) Positive lookahead to assert that what follows is a digit
• [A-Za-z\d!$%@#£€*?&]{8,} Match any of the charachters in the character class 8 or more times
• $ Assert position at the end of the line

const strings = [
  "A88888jf",
  "Aa88888jf",
  "Aa888jf",
  "AAAAAAAAAAA",
  "aaaaaaaaaaaaaa",
  "2222222222222222",
  "1sAdfe44",
  "$#fd#######"
];
let pattern = /^(?=.*[A-Z])(?=.*[a-z])(?=.*\d)[A-Za-z\d!$%@#£€*?&]{8,}$/;

strings.forEach((s) => {
  console.log(s + " ==> " + pattern.test(s));
});

Comments

[Nicolas]

This doesn't work pattern:{requiredPattern: "^(?=.*[A-Z])(?=.*[a-z])(?=.*d)[A-Za-zd!$%@#£€*?&]{8,}$", actualValue: "Test1234"}

[The fourth bird]

Why should Test1234 not match?

[Nicolas]

That's the problem, it's supposed to match, but it gives me the error cause it doesn't.

[The fourth bird]

@Nicolas Can you add the error to your question? Did you try it without the forward slash?