Compare an array element to particular string of characters in javascript

Question

I have an array of characters like :

var invalid_chars = ['<', '>', '$', '@', '&', '+', '(', ')', '[', ']', '{', '}',' ','`'];

and have a string like :

var id_val = $("#id_number").val(); //text field contains "mu 1$2@345"

So I want to restrict the invalid_chars to be entered in the filed.

For that I have the following code:

var id_val = $("#id_number").val();
var invalid_chars = ['<', '>', '$', '@', '&', '+', '(', ')', '[', ']', '{', '}',' ','`'];
if (in_array(invalid_chars,id_val)) {
  console.info("HI");
}

But it shows me error."ReferenceError: in_array is not defined"

Please help me out. Thanks in advance.

Sirko · Accepted Answer · 2012-12-14 14:42:04Z

3

in_array() is a PHP method. In JavaScript use indexOf().

answered Dec 14, 2012 at 14:42

Sirko

74.3k19 gold badges157 silver badges194 bronze badges

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

Comments

Alexis Abril · Accepted Answer · 2012-12-14 14:44:30Z

1

It looks like you're using jQuery already, which has an $.inArray() utility method.

answered Dec 14, 2012 at 14:44

Alexis Abril

6,4696 gold badges36 silver badges54 bronze badges

Comments

Pointy · Accepted Answer · 2012-12-14 14:48:09Z

1

You should turn your list of characters into a regular expression, in my opinion:

var badchars = /[<>$@&+()[\]{},` ]/;
if (badchars.test(id_val)) {
  // contains invalid characters
}

answered Dec 14, 2012 at 14:48

Pointy

415k62 gold badges600 silver badges631 bronze badges

Comments

antyrat · Accepted Answer · 2012-12-14 14:51:33Z

1

You need to write in_array function, simple example:

function in_array( arr, val ) {
    for( var i = 0; i < arr.length; i++) {
        if( arr[ i ] == val ) {
            return true;
        }
    }
}

or using regular expressions:

if( id_val.search( /[^0-9]/g ) == -1 )

or using regex you can strip all non-numeric characters:

var id_val = $("#id_number").val(); //text field contains "mu 1$2@345"
id_val = id_val.replace( /[^0-9]/g, '' );
console.log( id_val ); //text now field contains "12345"

or if you want wo allow latin char's as well:

[^0-9A-Za-z]

^ this will not include space char as well.

edited Dec 14, 2012 at 14:51

answered Dec 14, 2012 at 14:42

antyrat

27.7k9 gold badges78 silver badges77 bronze badges

Comments

Elias Van Ootegem · Accepted Answer · 2012-12-14 15:16:21Z

0

You can use indexOf on arrays, but older versions of MSIE's jScript engine don't support this method natively. So either augment the Array.prototype for those browsers (not without risks, obviously), or simply use a string of chars you want to test for:

var nonoChars = '<>$@&+()[]{},`';
for(var i = 0; i< id_val.length; i++)
{
    if (nonoChars.indexOf(id_val.charAt(i)) > -1)
    {
        alert('Char #' + (i + 1) + ' is not allowed!');
        return false;
    }
}
//input ok

But, in this case, a regex simply makes more sense:

if (id_val.match(/[<>$@&+()\[\]{},`]/))
{
    alert('Invalid input');
    return false;
}
//input ok

answered Dec 14, 2012 at 15:16

Elias Van Ootegem

76.7k10 gold badges123 silver badges160 bronze badges

Collectives™ on Stack Overflow

Compare an array element to particular string of characters in javascript

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related