What is the difference between the assignment operator "=" and the comparison operator "==" in PHP, and how does it impact IF-Abfragen?

The assignment operator "=" is used to assign a value to a variable, while the comparison operator "==" is used to compare two values. When writing IF-Abfragen (IF statements) in PHP, it's important to use the comparison operator "==" to check if two values are equal, rather than the assignment operator "=" which will always return true. This mistake can lead to unexpected behavior in your code.

// Incorrect usage of assignment operator "=" in IF-Abfragen
$a = 5;
$b = 10;

if($a = $b) {
    echo "Values are equal";
} else {
    echo "Values are not equal";
}

// Correct usage of comparison operator "==" in IF-Abfragen
$a = 5;
$b = 10;

if($a == $b) {
    echo "Values are equal";
} else {
    echo "Values are not equal";
}