CODEWITHSUNDEEP
phpisset
Suhail Gupta
Suhail Gupta

Reputation: 23206

isset() evaluates to true even when the textfields are empty. Why is that?

The first snippet takes data from the two text fields and sends to action script.php. The problem is both the if statements evaluate to true even if I do not enter anything in the text fields. Why is that ?

try.php

<form method='get' action='./action_script.php'>
        <input type="text" id="text_first" name="text_first" /> <br />
        <input type="text" id="text_second" name="text_second"/> <br />
        <input type="submit" id="submit" />
</form>

action_script.php

<?php

  if(isset($_GET['text_first'])) {
        echo "Data from the first text field : {$_GET['text_first']} <br>";
  }
  if(isset($_GET['text_second'])) {
        echo "Data from the second text field : {$_GET['text_second']} <br>";
  }

  echo "After the if statement <br />";

Upvotes: 3

Views: 5840

Answers (4)

dmbb
dmbb

Reputation: 1

This worked for me :

if ( (isset($_POST['DEVICEINPUT'])) && (!empty($_POST['DEVICEINPUT'])) && (trim($_POST['DEVICEINPUT']) !== null) ) {

....

}

Upvotes: 0

Bhadra
Bhadra

Reputation: 2104

When you are submitting the form without any values, empty values are posted for variables text_first and text_second, but in the $_GET array a key is set for them with null values, i.e $_GET['text_first']='' and 

$_GET['text_second']=''

,but the values are set for the two .

So if u want to check emptiness use empty() ,because isset() returns true as they are set

Upvotes: 0

EM-Creations
EM-Creations

Reputation: 4301

If the fields are present in the form it will evaluate to true. To check if a form has been properly submitted and has a value I use the following if statement:

if (isset($_GET['text']) && !empty($_GET['text'])) { // If the value is set and is not empty
    // Processing code here..
}

Upvotes: 0

Zoltan Toth
Zoltan Toth

Reputation: 47667

Because they both are set - the variables exist in the $_GET array. Even if their values are empty strings.

Try to check for emtpiness as well

 if( isset($_GET['text_first']) && $_GET['text_first'] !== '' )

or

if ( ! empty( $_GET['text_first'] ) ) {

Note that you don't need to use isset() because empty() does not generate a warning if the variable does not exist.

Upvotes: 8

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