Variable is name of memory location used to store some data.

In PHP no need to provide data types at the time of variable declaration because PHP is loosely types language .

Variable names start with ‘$’ symbol.

types of variable in PHP

Local variable :-

Variable declaration within the function comes under local variable .

Local variable of a function cannot be accessed from another function.

Global variable :-

Variable declaration outside of all function come under global variable.

Global variable can be accessed from any function within the script.

Note:- We can not access global variables directry from function by using ‘$’ GLOBALS keyword. We can access global variable by using ‘$ GLOBALS’ key from functions.

Variable variables :-

If we assign a variable name as the value of another variable comes under variable variables ,

Static variables :-

Static variable can remember previous value . we can assign value only one time into static variable.

Reference variable :-

It is an alias name of a variable . both refers the value of same address locations.

Super Global variable :

PHP support no of super global variable . these variable we can access from any web page in application. All super global variables are array data types available

In php four data types

Boolean
Integer
Float
String

Boolean data type in php

This data type can represent either true or false . In PHP value is 1 and value of false doesn’t any value.
is_bool : Using this function , we can check input variable is boolean or not.
(bool) var OR (boolean) var using this function , we convert variable into boolean variable.

Integer data type in php

This data type can store numeric value
is_int OR is_integer it is used to cheak input variable is integer or not .
(int)var ))OR (integer) var OR intval(var) Using this function , we convert variable into integer variable.

Float data type in photo

this data type can store decimal values .

is_float () this function cheacks input variuable is float or not.
(float)var Converts a variable into floating point number.

String data type in php

It is a collection of character.
In PHP , we can declar string in three ways.

By using single quotations
By using double quotations
By using heredoc syntax

NOTE Variable in double quotations returns value of variables.

Heredoc PHP suports heredoc syntax to avoid the conflicts what we getting with single and double quotations.

Compound data types

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Variables in PHP