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PHP

Posted by Carl Youngman
Carl Youngman
2,138 Points

Help with PHP

Could someone help me with the code below. I only want it to echo out 'book1' or 'book2'. at the moment it echos out both statements, which is what i would expect it to do. I'm not such how to select each element out of the array. I tried $mode_allowed[0] but it gives me an error.

thanks

$mode_allowed = array('book1', 'book2');

if (isset($_GET['book']) === true && in_array($_GET['book'] , $mode_allowed) === true){ $errors[] = 'Book 1'; }

if (isset($_GET['book']) === true && in_array($_GET['book'] , $mode_allowed) === true){ $errors[] = 'Book 2';

} else $errors[] = 'opps, we cant find book';

?>

<?php echo output_errors($errors); ?>

3 Answers

Randy Hoyt
STAFF
Randy Hoyt
Treehouse Guest Teacher
Randy Hoyt
Randy Hoyt
Treehouse Guest Teacher

The in_array function lets you look for a specific value inside of an array. If it finds the value in the array, it returns true; if it doesn't, then it returns false. Right now, this is your conditional:

if (isset($_GET['book']) === true && in_array($_GET['book'] , $mode_allowed) === true)

This asks the question "Is the GET variable book set, and is its value in the $mode_allowed array?"

If you change it to this --

    if (isset($_GET['book']) === true && in_array($_GET['book'] , $mode_allowed[0]) === true)

-- it produces an error because $mode_allowed[0] is a string, not an array. You can only use in_array if the second argument is actually an array.

The smallest change would be this:

    if (isset($_GET['book']) === true && $_GET['book'] == $mode_allowed[0])

This asks the question "Is the GET variable book set and does it have the same value as the first element in the array?"

Though I'm not sure why you are using an array at all. If you are going to hard-code the value you assign to $errors within the conditional, why not hard-code the value checked in the conditional?

    if (isset($_GET['book']) === true && $_GET['book'] == 'book1')

Does that help?

Carl Youngman
Carl Youngman
2,138 Points
Carl Youngman
Carl Youngman
2,138 Points

Thanks Randy. I was using an array because I was trying to edit some code I already had. Thanks for taking the time to explain what I was doing wrong. It really helps rather then just being told the answer.