How can I validate user input (characters and number) with javascript?

Question

From this example I tried to validate user input when a button was clicked.

$("#check_data").click(function () {
    var $userInput = $('#user_input'); //from HTML input box id="user_input"
    var pattern = " /*My user input always be like "AB1234567"*/ ";
    if ($userInput.val() == '' || !pattern.test($userInput.val())) {
        alert('Please enter a valid code.');
        return false;
    }
});

My user input input always be like "AB1234567" with this exact same characters but different 7 digits number. I'm new to Javascript and Jquery, if you have any better way to validate user input, please suggest it.

Thank you.

So the value is in the pattern of AB1234567, but it's not the exact value? Sounds like you need to use regular expressions. — Doug F
– Doug F, Commented Feb 20, 2019 at 11:47
the pattern you need: [a-zA-Z]{2}[0-9]{7} suppose to be any letter max 2 any number max 7 — Gabriele Carbonai
– Gabriele Carbonai, Commented Feb 20, 2019 at 11:52

Amal US · Accepted Answer · 2019-02-20 12:05:53Z

1

You can use below regex Expression to check

/[A-Za-z0-9]/g

Your code could be like this

    var _pattern=/[A-Za-z0-9]/g
    if($userInput.val().match(_pattern))
    {
        //your code goes here..
    }

Thanks

answered Feb 20, 2019 at 12:05

Amal US

213 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

StudioTime · Accepted Answer · 2019-02-20 11:56:05Z

0

You can use the below pattern to check

/^AB\d{7}$/

You can change code to

var pattern = '/^AB\d{7}$/';
  if ($userInput.val() == '' || !pattern.test($userInput.val()))
  {
     alert('Please enter a valid code.');
     return false;
  }

\d{7} matches 7 digits in the range [0-9]

edited Feb 20, 2019 at 11:56

StudioTime

24.4k40 gold badges129 silver badges217 bronze badges

answered Feb 20, 2019 at 11:49

melvin

2,6211 gold badge21 silver badges39 bronze badges

Comments

Rohit Mittal · Accepted Answer · 2019-02-20 11:56:47Z

0

You can follow below code for this:

if ($userInput.val().match(/[^a-zA-Z0-9 ]/g))
{
    // it is a valid value.

} else {
    // show error here
}

Hope it helps you.

answered Feb 20, 2019 at 11:56

Rohit Mittal

2,1142 gold badges12 silver badges21 bronze badges

Comments

j1rjacob · Accepted Answer · 2019-02-20 12:09:38Z

0

Try this one.

$("#check_data").click(function(){
  var $userInput = $('#user_input').val();
  var pattern = /^AB[0-9]{7}?/g;
  if(!$userInput.match(pattern)){
      alert('Please enter a valid code.');
      return false;
  }
});

answered Feb 20, 2019 at 12:09

j1rjacob

43012 silver badges27 bronze badges

Collectives™ on Stack Overflow

How can I validate user input (characters and number) with javascript?

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related