How to write this Regular Expression

Question

How do i write a regular expression which accepts only value "1" in the textbox and it should not accept zero or greter than "1"

Answer 1

/^1$/

… but for a "Must be this value, exactly this value, and nothing but this value" test, you would be much better off with a simple string comparison.

Answer 2

if (theTextBoxValue == "1") {
   // accept
} else {
  // reject
}

You don't need regex for this simple task. And, if you only accept "1" in a user input, why provide such an input to the user at all?

Answer 3

/^1$/ but a simple == "1" will be enough in most languages (or .equals("1")).

Answer 4

Don't think you want to use regex for this.

Pattern: ^1$

Answer 5

Hi, I saw your previous question (using the jquery validationEngine), and I was intrigued by it so I started looking.

The problem with using a funcCall (as you were trying in the old post) is that the function is called without any context (has no arguments, and has this == window), so you can't tell which input field is being validated.(I solved this with a trick - see example & comments linked below).

Another solution I found was using regex(as you are trying now). This is the entry you have to add to the languages file:

"isOne":{
        "regex":"/^1$/",
        "alertText":"* Only '1' is valid [regex]"
    }

This is how you use it on the input field:

<input type="text" class="validate[custom[isOne]]">

And this is how you start the validation engine:

$('#form').validationEngine({
    validationEventTriggers:"change"
});

You can view a working example using both function and regex here