What common mistakes can be made when using if statements in PHP?

One common mistake when using if statements in PHP is forgetting to use double equals (==) for comparison instead of a single equals sign (=), which is used for assignment. This can lead to unintended consequences and errors in your code. To fix this issue, always use double equals (==) when comparing values in if statements.

// Incorrect usage of single equals sign for comparison
$number = 5;

if($number = 5) {
    echo "Number is equal to 5";
}

// Corrected usage of double equals sign for comparison
$number = 5;

if($number == 5) {
    echo "Number is equal to 5";
}