[php] Difference between if () { } and if () : endif;

Are there any differences between...

if ($value) {

}

...and...

if ($value):

endif;

?

Here's where you can find it in the official documentation: PHP: Alternative syntax for control structures

They are indeed both the same, functionally.

But if the endif is getting too far from the correspondent if I think it's much better practice to give a referencing comment to it. Just so you can easily find where it was open. No matter what language it is:

if (my_horn_is_red or her_umbrella_is_yellow)
{

    // ...

    // let's pretend this is a lot of code in the middle

    foreach (day in week) {
        sing(a_different_song[day]);
    }

    // ...

} //if my_horn_is_red

That actually applies to any analogous "closing thing"! ;)

Also, in general, editors deal better with curly brackets, in the sense they can point you to where it was open. But even that doesn't make the descriptive comments any less valid.

It all depends, personally I prefer the traditional syntax with echos and plenty of indentations, since it's just so much easier to read.

<?php
    if($something){
        doThis();
    }else{
        echo '<h1>Title</h1>
            <p>This is a paragraph</p>
            <p>and another paragraph</p>';
    }
?>

I agree alt syntax is cleaner with the different end clauses, but I really have a hard time dealing with them without help from text-editor highlighting, and I'm just not used to seeing "condensed" code like this:

<?php if( $this->isEnabledViewSwitcher() ): ?>
<p class="view-mode">
    <?php $_modes = $this->getModes(); ?>
    <?php if($_modes && count($_modes)>1): ?>
    <label><?php echo $this->__('View as') ?>:</label>
    <?php foreach ($this->getModes() as $_code=>$_label): ?>
        <?php if($this->isModeActive($_code)): ?>
            <strong title="<?php echo $_label ?>" class="<?php echo strtolower($_code); ?>"><?php echo $_label ?></strong>&nbsp;
        <?php else: ?>
            <a href="<?php echo $this->getModeUrl($_code) ?>" title="<?php echo $_label ?>" class="<?php echo strtolower($_code); ?>"><?php echo $_label ?></a>&nbsp;
        <?php endif; ?>
    <?php endforeach; ?>
    <?php endif; ?>
</p>
<?php endif; ?>

I would use the first option if at all possible, regardless of the new option. The syntax is standard and everyone knows it. It's also backwards compatible.

I think that it's particularly clearer when you're using a mix of ifs, fors and foreaches in view scripts:

<?php if ( $this->hasIterable ): ?>
    <h2>Iterable</h2>
    <ul>
    <?php foreach ( $this->iterable as $key => $val ):?>
        <?php for ( $i = 0; $i <= $val; $i++ ): ?>
        <li><?php echo $key ?></li>
        <?php endfor; ?>
    <?php endforeach; ?>
    </ul>
<?php elseif ( $this->hasScalar ): ?>
    <h2>Scalar</h2>
    <?php for ( $i = 0; $i <= $this->scalar; $i++ ): ?>
    <p>Foo = Bar</p>
    <?php endfor; ?>
<?php else: ?>
    <h2>Other</h2>
    <?php if ( $this->otherVal === true ): ?>
    <p>Spam</p>
    <?php else: ?>  
    <p>Eggs</p>  
    <?php endif; ?>
<?php endif; ?>

as opposed to:

<?php if ( $this->hasIterable ){ ?>
    <h2>Iterable</h2>
    <ul>
    <?php foreach ( $this->iterable as $key => $val ){?>
        <?php for ( $i = 0; $i <= $val; $i++ ){ ?>
        <li><?php echo $key ?></li>
        <?php } ?>
    <?php } ?>
    </ul>
<?php } elseif ( $this->hasScalar ){ ?>
    <h2>Scalar</h2>
    <?php for ( $i = 0; $i <= $this->scalar; $i++ ){ ?>
    <p>Foo = Bar</p>
    <?php } ?>
<?php } else { ?>
    <h2>Other</h2>
    <?php if ( $this->otherVal === true ){ ?>
    <p>Spam</p>
    <?php } else { ?>  
    <p>Eggs</p>  
    <?php } ?>
<?php } ?>

This is especially useful for long control statements where you might not be able to see the top declaration from the bottom brace.

There is no technical difference between the two syntaxes. The alternative syntax is not new; it was supported at least as far back as PHP 4, and perhaps even earlier.

You might prefer the alternative form because it explicitly states which control structure is ending: endwhile, for example, can only terminate a while block, whereas if you encounter a brace, it could be closing anything.

You might prefer the traditional syntax, though, if you use an editor that has special support for braces in other C-like syntaxes. Vim, for example, supports several keystrokes for navigating to matching braces and to the starts and ends of brace-delimited blocks. The alternative syntax would break that editor feature.

I think it's a matter of preference. I personally use:

if($something){
       $execute_something;
}

I feel that none of the preexisting answers fully identify the answer here, so I'm going to articulate my own perspective. Functionally, the two methods are the same. If the programer is familiar with other languages following C syntax, then they will likely feel more comfortable with the braces, or else if php is the first language that they're learning, they will feel more comfortable with the if endif syntax, since it seems closer to regular language.

If you're a really serious programmer and need to get things done fast, then I do believe that the curly brace syntax is superior because it saves time typing

if(/*condition*/){
    /*body*/ 
}

compared to

if(/*condition*/):
    /*body*/
endif;

This is especially true with other loops, say, a foreach where you would end up typing an extra 10 chars. With braces, you just need to type two characters, but for the keyword based syntax you have to type a whole extra keyword for every loop and conditional statement.

I think this say it all:

this alternative syntax is excellent for improving legibility (for both PHP and HTML!) in situations where you have a mix of them.

http://ca3.php.net/manual/en/control-structures.alternative-syntax.php

When mixing HTML an PHP the alternative sytnax is much easier to read. In normal PHP documents the traditional syntax should be used.

Both are the same.

But: If you want to use PHP as your templating language in your view files(the V of MVC) you can use this alternate syntax to distinguish between php code written to implement business-logic (Controller and Model parts of MVC) and gui-logic. Of course it is not mandatory and you can use what ever syntax you like.

ZF uses that approach.

Personally I prefer making it in two seperate sections but within the same PHP like:

<?php 
    if (question1) { $variable_1 = somehtml; }
    else { $variable_1 = someotherhtml; } 

    if (question2) {
        $variable_2 = somehtml2;
    }

    else { 
        $variable_2 = someotherhtml2;
    }         

etc.
$output=<<<HERE
htmlhtmlhtml$variable1htmlhtmlhtml$varianble2htmletcetcetc
HERE;
echo $output;

?>

But maybe it is slower?

I think that it really depends on your personal coding style. If you're used to C++, Javascript, etc., you might feel more comfortable using the {} syntax. If you're used to Visual Basic, you might want to use the if : endif; syntax.

I'm not sure one can definitively say one is easier to read than the other - it's personal preference. I usually do something like this:

<?php
if ($foo) { ?>
   <p>Foo!</p><?php
} else { ?>
   <p>Bar!</p><?php
}  // if-else ($foo) ?>

Whether that's easier to read than:

<?php
if ($foo): ?>
   <p>Foo!</p><?php
else: ?>
   <p>Bar!</p><?php
endif; ?>

is a matter of opinion. I can see why some would feel the 2nd way is easier - but only if you haven't been programming in Javascript and C++ all your life. :)

I used to use the curly braces but now a days I prefer to use this short-hand alternative syntax because of code readability and accessibility.

At our company, the preferred way for handling HTML is:

<? if($condition) { ?>
   HTML content here
<? } else { ?>
   Other HTML content here
<? } ?>

In the end, it really is a matter of choosing one and sticking with it.

I used to use curly brackets for "if, else" conditions. However, I found "if(xxx): endif;" is more semantic if the code is heavily wrapped and easier to read in any editors.

Of course, lots editors are capable of recognise and highlight chunks of code when curly brackets are selected. Some also do well on "if(xxx): endif" pair (eg, NetBeans)

Personally, I would recommend "if(xxx): endif", but for small condition check (eg, only one line of code), there are not much differences.

I personally really hate the alternate syntax. One nice thing about the braces is that most IDEs, vim, etc all have bracket highlighting. In my text editor I can double click a brace and it will highlight the whole chunk so I can see where it ends and begins very easily.

I don't know of a single editor that can highlight endif, endforeach, etc.

In the end you just don't want to be looking for the following line and then having to guess where it started:

<?php } ?>

Technically and functionally they are the same.