I am not able to figure out what we really mean when we echo javascript. Does it mean; the function inside script will execute inevitably? I mean, will it execute with out even being called? I've seen long scripts that seem to include a plete page inside an echo statement.

echo "<script type='text/javascript'>
$(function(){
blah blah blah
});
</script>";

I am not able to figure out what we really mean when we echo javascript. Does it mean; the function inside script will execute inevitably? I mean, will it execute with out even being called? I've seen long scripts that seem to include a plete page inside an echo statement.

echo "<script type='text/javascript'>
$(function(){
blah blah blah
});
</script>";

• php
• javascript
• echo

4 Answers 4

It means exactly the same thing as when we echo HTML: that text will be sent to the browser. What the browser does with it is independent of what PHP does.

echo is how you print output in PHP, it doesn't do anything special otherwise.

You can often see examples like yours in poorly organized, messy code. Like you say:

I've seen long scripts that seem to include a plete page inside an echo statement.

People get into a bad habit of "echoing" everything, rather than, in your case, using an external javascript file, or learning to break into or out of a PHP block for view logic.

<p>This is a variable: <?php echo $var; ?></p>

Usually should be preferred to:

echo "<p>This is a variable: $var</p>";

In general, you should avoid mixing HTML, CSS, and JavaScript into your PHP code unless it's in a template or view file. Just remember there are a lot of inexperienced coders out there and you shouldn't imitate everything you see.

It's better to inject PHP into your HTML, not the other way around.

With your given statement,

 echo "<script type='text/javascript'>
      $(function(){
      blah blah blah
      });
      </script>"; // You had a non useful " above

The output on the page will only be:

 <script type='text/javascript'>
      $(function(){
      blah blah blah
      });
      </script>

It won't execute the function.

$(function() {}) is a shotcut to $(document).ready(function() { })

The content of this function will be executed when the DOM is ready (a little bit before the page is pletely loaded)