Question

I am new to regex. I need a regex for JavaScript code that allows special character * in the beginning of text input, but not anywhere else in the text.

example : it should allow *text,
it should not allow *text*abcd

I would need a similar regex for PHP as well.

I have tried using “/^\s*/”, but this doesn’t work. Anyways I dont have anyidea of regex. I have started learning it.

Thanks
Dora

Answer 1

Part of learning how to use regex is knowing when you don’t need it. In this case a solution without regex would suffice, for PHP:

if (strrpos($str, '*') > 0) {
  // invalid position of *
}

For JavaScript:

if (str.lastIndexOf('*') > 0) {
    // invalid position for *
}

It basically finds the last position of the special character; if it appears in the string and is not the first character, the code inside the condition gets executed.