PHP变量值在For Else语句中意外更改

Question

In the following loop the first var_dump is int(2). In the last var_dump the value is int(0). I don't understand where the value of $total_gals changes.

<?php
$total_gals  = count( glob("images/*", GLOB_ONLYDIR) ); 
$loadnum = 0;
var_dump($total_gals);
if ($total_gals = 0) {
    echo "<script>alert('No Galleries to Load');</script>";
    var_dump($total_gals);
} elseif ($total_gals > 5) {
    $loadnum = 5;
} else {
    $loadnum == $total_gals;
}
var_dump($total_gals);
?>

Answer 1

Because if ($total_gals = 0) { needs to be if ($total_gals == 0) {

Without the second = you're assigning 0 to the variable which always evaluates to true for the if statement.