PHP is one of the most popular programming languages
these days. For a website designer and developer it is recommended to learn
this form basic to advance level.
In the series of our blogs of web development and
design I will try my best to make you learn PHP in one of the easiest ways.
Before you start you have to know some important starting points for PHP.
PHP is server side scripting. This is open source
software and it is free to download and use. If your server supports PHP then it is fine
but if not you have to install it form some source.
Basic
Syntax:
PHP starts always with <?php and end with ?>.
PHP file contains .php extension. PHP contains some of the HTML Tags along with
PHP scripting code.
Comments
in PHP:
For the reuse purpose of PHP commenting is a good
way. You should write Comments in front of every function. The commenting is
written by adding /* in the beginning and */ at the end of your sentence.
Example:
/* This is comment*/
Simple
Program:
This is somehow similar to HTML syntax.
<html>
<body>
<?php
echo "Hello World";
?>
</body>
</html>
<body>
<?php
echo "Hello World";
?>
</body>
</html>
·
There are two basic statements echo and
print.
·
Every code line ends with semicolon.
Variables:
Same like the algebraic variables we read in mathematics,
php variables hold the values.
Like x=5, y=10 etc….and finally z= x+y.
Variable
naming:
·
Starts with $ sign.
·
Name of the variable should start with underscore.
·
These can only be alpha numeric.
·
Can’t hold space in the naming.
·
Case
sensitive.
·
Variable without any value is null
variable.
·
Data type doesn’t need to define like we
do in C or C++.
Example:
<?php
$txt="MyProgram!";
$x=16;
?>
$txt="MyProgram!";
$x=16;
?>
There are four kinds of variable:
·
Local
·
Global
·
Static
·
Parameter
Local
Scope:
<?php
$a = 5; // global scope
function myTest()
{
echo $a; // local scope
}
myTest();
?>
$a = 5; // global scope
function myTest()
{
echo $a; // local scope
}
myTest();
?>
Global
Scope:
<?php
$a = 5;
$b = 10;
function myTest()
{
global $a, $b;
$b = $a + $b;
}
myTest();
echo $b;
?>
$a = 5;
$b = 10;
function myTest()
{
global $a, $b;
$b = $a + $b;
}
myTest();
echo $b;
?>
Also it can be written as:
<?php
$a = 5;
$b = 10;
function myTest()
{
$GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
}
myTest();
echo $b;
?>
$a = 5;
$b = 10;
function myTest()
{
$GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
}
myTest();
echo $b;
?>
Static Scope:
static $rememberMe;
Parameters:
function
myTest($para1,$para2,...)
{
// function code
}
So here were some basic practices for PHP. Remember!
Only practice can make a person perfect in coding.
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