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phpgetboolean

Passing a boolean through PHP GET

Pretty simple question here, not sure the answer though. Can I pass a boolean variable through get? For example:

http://example.com/foo.php?myVar=true

then I have

$hopefullyBool = $_GET['myVar'];

Is $hopefullyBool a boolean or a string? My hypothesis is that it's a string but can someone let me know? Thanks

Solution

  • All GET parameters will be strings (or an array of strings) in PHP. Use filter_var (or filter_input) and FILTER_VALIDATE_BOOLEAN:

    Returns TRUE for "1", "true", "on" and "yes". Returns FALSE otherwise.

    If FILTER_NULL_ON_FAILURE is set, FALSE is returned only for "0", "false", "off", "no", and "", and NULL is returned for all non-boolean values.

    $hopefullyBool = filter_var($_GET['myVar'], FILTER_VALIDATE_BOOLEAN);

    For INPUT vars that can be arrays there is filter_var_array and filter_input_array.

    Another way to get the type boolean, pass something that evaluates to true or false like string 0 or 1:

    http://example.com/foo.php?myVar=0
http://example.com/foo.php?myVar=1

    Then cast to boolean:

    $hopefullyBool = (bool)$_GET['myVar'];

    If you want to pass string true or false then another way:

    $hopefullyBool = $_GET['myVar'] == 'true' ? true : false;

    But I would say that filter_var with FILTER_VALIDATE_BOOLEAN was meant for this.