Why Do I Need Parentheses for Nested Ternary Operators?

Nested Ternary Operators: A Puzzle Solved

In the realm of programming, nested ternary operators can be a valuable tool for concise conditional statements. However, implementing them can sometimes be tricky. One recent challenge encountered by a user was utilizing isset() in a nested form:

isset($_POST['selectedTemplate'])?$_POST['selectedTemplate']:isset($_GET['selectedTemplate'])?$_GET['selectedTemplate']:0

The user faced an issue with this expression, and sought assistance from the programming community. Let's delve into the solution that emerged:

For nested ternary operators to function correctly, they must be wrapped within parentheses. This ensures that the expressions are evaluated in the intended order. Here's the corrected code:

$selectedTemplate = isset($_POST['selectedTemplate'])
                  ? $_POST['selectedTemplate']
                  : (
                       isset($_GET['selectedTemplate'])
                       ? $_GET['selectedTemplate']
                       : 0
                  );

However, for improved maintainability and clarity, using an if/else statement is a more recommended approach:

$selectTemplate = 0;

if (isset($_POST['selectedTemplate'])) {
    $selectTemplate = $_POST['selectedTemplate'];
} elseif (isset($_GET['selectedTemplate'])) {
    $selectTemplate = $_GET['selectedTemplate'];
}

Lastly, for simplicity and ease of use, it's worth considering $_REQUEST:

$selectedTemplate = isset($_REQUEST['selectedTemplate'])
                  ? $_REQUEST['selectedTemplate']
                  : 0;

Remember, the choice of approach ultimately depends on the specific requirements of your application. Happy coding, and may your ternaries be flawlessly nested!

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