CODEWITHSUNDEEP
javascript
zellman01
zellman01

Reputation: 33

Javascript toLowerCase() undefined error

I know this has been put out too many times, but none of the questions fix the problem I have. It gives me the following error every time I run the function:

TypeError: Cannot read property 'toLowerCase' of undefined

Here's the code it's running:

global.toId = function(text) {
    return text.toLowerCase().replace(/[^a-z0-9]/g, '');
};

Upvotes: 3

Views: 13353

Answers (3)

badrul
badrul

Reputation: 71

In ES2020, you can use optional chaining (?.)

global.toId = function(text) {
    return text?.toLowerCase().replace(/[^a-z0-9]/g, '');
};

Upvotes: 4

Ehsan
Ehsan

Reputation: 12969

this help you :

<!DOCTYPE html>
<html>
<head>
</head>

    <body>

        <script>

            var str = "EHSAN";

            var toId  = function(text) {

            return str.toLowerCase().replace(/[^a-z0-9]/g, '');

            }

           alert(toId());

        </script>

    </body>

</html>

Upvotes: 0

koala
koala

Reputation: 38

You can add a protection with:

if(typeof text === 'string')

In the function:

global.toId = function(text) {
   if(typeof text === 'string')
      return text.toLowerCase().replace(/[^a-z0-9]/g, '');
   else
      console.log('incorrect input');
}

Upvotes: 0

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