What common mistakes are 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 (=). This mistake can lead to unintended variable assignment instead of comparison. To solve this issue, always use double equals (==) for comparison in if statements.

// Incorrect usage of if statement
$number = 5;
if($number = 10) {
    echo "Number is 10";
}

// Correct usage of if statement
$number = 5;
if($number == 10) {
    echo "Number is 10";
}