PHP103
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PHP Start Symbols
<? <?php
- both of these groups of symbols indicate the start of a section of PHP code - either can be used
PHP End Symbols
?>
- these symbols indicate the end of a section of PHP code
Commenting in PHP
<?
echo 'This would be printed out';
// THIS IS A SINGLE LINE COMMENT AND WON'T BE PRINTED
# BELIEVE IT OR NOT, THIS IS ALSO A SINGLE LINE COMMENT
/* THIS SYMBOL PAIR
STARTS A MULTI-LINE COMMENT BLOCK
THAT ONLY ENDS WHEN YOU GET TO THE FOLLOWING SYMBOL PAIR
*/
echo 'This would also be printed out';
?>
- as shown above, there are a number of ways to include comments in PHP code
Outputing in PHP
There are essentially two ways of outputting in PHP - echo and print - there is very little difference between the two - at the high-performance end of PHP, echo is fractionally faster, however print can be used in complex expressions - for the basic level of PHP there is no difference.
<?
echo 'Hello';
echo "World";
print 'Where are';
print "you?";
?>
- all of the above are valid examples of outputting
Which symbol to use ' or "?
Again, these are essentially the same.
How do I print a ' or " in my output?
This is a very important note, that often causes problems for the novice PHP programmer.
If you try and do this:
<?
echo "My name is "Matthew" - yes it is!";
?>
You would probably expect the output to be:
My name is "Matthew" - yes it is!
But what you will actually get is something like:
To output speech marks, either single (') or double (") in echo or print statements you must ESCAPE them
Escaping Speech Marks
To ESCAPE speech marks, you put a backslash symbol only in front of the ones you want to print out.
So the example in the previous section becomes:
<?
echo "My name is \"Matthew\" - oh yes it is!";
?>
And the output you get is:
My name is "Matthew" - oh yes it is!
