What debugging techniques can be employed to identify errors in PHP code, especially when dealing with variable assignments and evaluations?

When debugging PHP code involving variable assignments and evaluations, one useful technique is to use var_dump() or print_r() functions to display the contents of variables at different points in the code. This can help identify if the variables are being assigned the correct values or if there are any unexpected changes. Additionally, using echo statements to print out intermediate results can also aid in pinpointing where the issue lies.

// Example PHP code snippet for debugging variable assignments and evaluations

$variable1 = 10;
$variable2 = 5;

// Debugging variable assignments
var_dump($variable1);
var_dump($variable2);

// Debugging variable evaluations
$result = $variable1 + $variable2;
echo "The result of the evaluation is: " . $result;