PHP Syntax
You cannot view the PHP source code by selecting
"View source" in the browser - you will only see the output from the
PHP file, which is plain HTML. This is because the scripts are
executed on the server before the result is sent back to the browser
Basic PHP Syntax
A PHP file normally contains HTML
tags, just like an HTML file, and some PHP scripting
code.
Below, we have an example of a
simple PHP script which sends the text "Hello World"
to the browser:
<?php echo "Hello World"; ?>
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A PHP scripting block always
starts with <?php and ends with ?>. A
PHP scripting block can be placed anywhere in the
document.
Each code line in PHP must end
with a semicolon. The semicolon is a separator and
is used to distinguish one set of instructions from
another.
There are two basic statements to
output text with PHP: echo and print.
In the example above we have used the echo statement
to output the text "Hello World".
Variables in PHP
All variables in PHP start with a
$ sign symbol. Variables may contain strings,
numbers, or arrays.
Below, the PHP script assigns the
string "Hello World" to a variable called $txt:
<?php
$txt="Hello World";
echo $txt;
?>
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To concatenate two or more
variables together, use the dot (.) operator:
<?php
$txt1="Hello World";
$txt2="1234";
echo $txt1 . " " . $txt2 ;
?>
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The output of the script above
will be: "Hello World 1234".
Comments in PHP
In PHP, we use // to make a
single-line comment or /* and */ to make a large
comment block.
/*
This is
a comment
block
*/
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