PHP Variables are an essential element in php programming . An efficient way for storing data or information in the content of the PHP code are done by using Variable.
PHP variable are also use in condition checking, looping and branching.
Dear learner in this tutorial i discussed details about PHP variables. I Hope everybody must be benefited form this tutorial.
Some Major Rules for PHP Variables:
1. A PHP variable begin with a dollar sign ($).
2. Variable name must begin with a letter or a underscore ( _ ) character.
3. Variable names in php are case sensitive that is ( A and a are two different variables ).
4. Variable name can not contain a space.
5. Variable name can contain Numeric ,Characters and underscore (0-9 , A-Z, a-z , _ ).
PHP has total eight kinds of data types that is used in php variable :
1. Integers: are complete numbers For Example: 65667
2. Strings: are set of character or word: For Example: ‘PHP support string variable.’
3. Double: are floating point number Such as: 3.1416
4. Null: is a special data type in php that has only one value: Null
5. Booleans: have only two values ‘true’ or ‘false‘.
6. Resources: are special type of variables that holds references to resources external to PHP.
7. Object: are instance of developer-defined classes.
8. Arrays: are indexed and named collections of other values.
Use of PHP Variables:
They are complete numbers For Example: 65667 . These are the simplest type .They can be positive or negative number . Integers can be assigned to a variables or they can also be used in expressions. For Example:
|$int_1stvariable = 121212;$second_int = -2222+2222;|
Strings are set of character or word: For Example: ‘PHP support string variable.’
Example of php Strings variable:
|$string_var1 = “this is a string in double quotation”;
$string_var2 = “my name is, Mr. X”;
$string_var31 = “this string has thirty-one characters”;
$string_null = “”; // a string with zero/null charactersAnother example of php Strings variable:<?php
$text2=”Have a nice day.”;
echo $text1 . ” ” . $text2;
?>Output:Hello World! Have a nice day.
Purpose: In php strlen () function is used to return the length of a string.
echo strlen (“Hello world”);
The output of the above code is :
Purpose: In php strpos() function is used for searching
text/character within a string.
Output of the above code :
They like 4.99999 or 2653.251
|$first_num = 3.50;
$second_num = 35.21;
$ sum= $first_num + $second_num;
print(.$first_num + $second_num = $sum);
They have only two values ‘true’ or ‘false‘.
print(“Wel come to boolean data type “);else
print(“Wel come to php programming”);
Null is a special kind of data type in php that has only one value:NULL.
|$null_variable = NULL;|
Variable Scope in PHP:
Variable Scope can be defined as the range of availability in a program in which it is declared.
PHP variables can be declared as :
1. Global variables
$t1 = 5;
$t2 = 10; // here t1 & t2 are global variablesfunction total()
global $t1, $t2;
$sum = $t1 + $t2;
2. Local variables.
|<?php$roll = 21; // global scopefunction myroll()
echo $roll; // local scope}myroll();?>
3. Static variables.
For Example: static $victorday;
4. Function Parameters.
function myfunction ($num1,$num2,…)
// function code