how to use is null in mysql - Wikitechy https://www.wikitechy.com/interview-questions/tag/how-to-use-is-null-in-mysql/ Interview Questions Tue, 02 Aug 2022 12:16:39 +0000 en-US hourly 1 https://wordpress.org/?v=6.9 https://www.wikitechy.com/interview-questions/wp-content/uploads/2025/10/cropped-wikitechy-icon-32x32.png how to use is null in mysql - Wikitechy https://www.wikitechy.com/interview-questions/tag/how-to-use-is-null-in-mysql/ 32 32 What is NULL in PHP ? https://www.wikitechy.com/interview-questions/php/what-is-null-in-php/ https://www.wikitechy.com/interview-questions/php/what-is-null-in-php/#respond Tue, 02 Aug 2022 12:16:39 +0000 https://www.wikitechy.com/interview-questions/?p=4557
  • In PHP null () function is an inbuilt function which is used to find whether a variable is NULL or not.
  • If it returns True the given variable is null, otherwise it returns False.
  • If the value of $x is equal to NULL it returns true and it is an identical comparison operator.
  • In PHP null is a special data type which can have only one value that is NULL.
  • NULL data type is a variable that has no value assigned to it and then any variable can be empty by setting the value NULL to the variable.

    • Sample Code

    <!DOCTYPE html>
    <html>
    <body>

    <?php
    $apple = 0;
    echo "apple is " . is_null($a) . "<br>";

    $orange = null;
    echo "orange is " . is_null($b) . "<br>";

    $grape = "null";
    echo "grape is " . is_null($c) . "<br>";

    $watermelon = NULL;
    echo "watermelon is " . is_null($d) . "<br>";
    ?>

    </body>
    </html>

    Output

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