How can the use of foreach() function in PHP lead to errors like "Invalid argument supplied for foreach()"?

When using the foreach() function in PHP, the "Invalid argument supplied for foreach()" error occurs when the function is called on a variable that is not an array or an object that does not implement the Traversable interface. To solve this issue, you should always ensure that the variable passed to foreach() is an array or an object that can be iterated over.

// Check if the variable is an array before using foreach()
if (is_array($variable)) {
    foreach ($variable as $item) {
        // Iterate over the array
    }
} else {
    // Handle the case where $variable is not an array
}