Don’t Use PHP in JS Condition Check

// todo

1. php true vs false echo in js
2. check if it’s true in php, with null, bool string object
3. js if() with null, bool, string, int, object

Don’t use PHP in JS Condition Check.

<script>

      if ('false') {
          alert('hi');
      }
  </script>

Above code alerts “hi”. That’s alright.

<?php $demo = "false"; ?>

<script>

    if (<?php echo $demo; ?>) {
        alert('hi');
    }
</script>

Above code has no alert

<?php $demo = "false"; ?>

<script>

    if ('<?php echo $demo; ?>') {
        alert('hi');
    }
</script>

Above code alerts “hi”. That’s alright.

<?php $demo = "demo"; ?>

<script>

    if ('<?php echo $demo; ?>') {
        alert('hi');
    }
</script>

Above code alerts “hi”.

<script>

      <?php $demo = "true"; ?>

      if (<?php $demo ; ?>) {
          alert("hi");
      }
  </script>

no alert

<script>

    <?php $demo = "true"; ?>

    if (<?php echo $demo ; ?>) {
        alert("hi");
    }
</script>

Alert !

Conclusion:

1. Try not to use php in js
2. Use it the following way:

<?php if($first_condition): ?>
  /*$first_condition is true*/
<?php elseif ($second_condition): ?>
  /*$first_condition is false and $second_condition is true*/
<?php else: ?>
  /*$first_condition and $second_condition are false*/
<?php endif; ?>