Monday, June 25, 2012

Variables in php


Variables are "stores" for storing information.this is simple definition

are you remember Mathematical equations that we study in the school

a=5     s=7     q=a+s  These letters are called variables

ii give you simple example if we have store Contains computer ,laptop , mobile phone ok

this store have name store a  which easy to say store a   or say his all Contents

there is many reasons to use Variables and i will give you some in it

how can we write  Variables in php

Variables in PHP starts with a $ sign, followed by the name of the variable example ($test)
The variable name must begin with a letter or the underscore character "_" example ($_test or $test)
A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
A variable name should not contain spaces
Variable names are case sensitive (z and Z are two different variables)

variables is  created when you give  a value to it

example

<?php
$var=55;
echo $var ;
echo"<br>";
$var1=66;
echo $var+$var1;
$var_text= "    hi every body";
echo $var_text;
?>
result
55
121hi every body


remember When we assign a text value to a variable, put quotes around the value. like   $var_text.


PHP is a Loosely Typed Language

In PHP, a variable does not need to be declared before adding a value to it.
In the example above, notice that we did not have to tell PHP which data type the variable is.
PHP automatically converts the variable to the correct data type, depending on its value.
In a strongly typed programming language, you have to declare (define) the type and name of the variable before using it.

No comments:

Post a Comment