Tuesday, 13 June 2017

php data types

PHP DATA TYPES

PHP data types are used to hold different types of data or values. PHP supports 8 primitive data types that can be categorized further in 3 types:
  1. Scalar Types
  2. Compound Types
  3. Special Types

PHP Data Types: Scalar Types

There are 4 scalar data types in PHP.
  1. boolean
  2. integer
  3. float
  4. string

PHP Data Types: Special Types

There are 2 special data types in PHP.
  1. resource
  2. NULL

PHP String

A string is a sequence of characters, like “Hello world!”.
A string can be any text inside quotes. You can use single or double quotes:
<?php
$x = "Hello world!";
$y = 'Hello world!';

echo $x;
echo "<br>";
echo $y;
?>

PHP Integer

An integer data type is a non-decimal number between -2,147,483,648 and 2,147,483,647.
Rules for integers:
  • An integer must have at least one digit
  • An integer must not have a decimal point
  • An integer can be either positive or negative
  • Integers can be specified in three formats: decimal (10-based), hexadecimal (16-based – prefixed with 0x) or octal (8-based – prefixed with 0)
In the following example $x is an integer. The PHP var_dump() function returns the data type and value:
<?php
$x = 5985;
var_dump($x);
?>

PHP Float

A float (floating point number) is a number with a decimal point or a number in exponential form.
In the following example $x is a float. The PHP var_dump() function returns the data type and value:
<?php
$x = 10.365;
var_dump($x);
?>

PHP Boolean

A Boolean represents two possible states: TRUE or FALSE.
$x = true;
$y = false;
Booleans are often used in conditional testing.

PHP Array

An array stores multiple values in one single variable.
In the following example $cars is an array. The PHP var_dump() function returns the data type and value:
<?php
$cars = array("Volvo","BMW","Toyota");
var_dump($cars);
?>

PHP Object

An object is a data type which stores data and information on how to process that data.
In PHP, an object must be explicitly declared.
<?php
class Car {
function Car() {
$this->model = "VW";
}
}

// create an object
$herbie = new Car();

// show object properties
echo $herbie->model;
?>

PHP NULL Value

Null is a special data type which can have only one value: NULL.
A variable of data type NULL is a variable that has no value assigned to it.
Tip: If a variable is created without a value, it is automatically assigned a value of NULL.
Variables can also be emptied by setting the value to NULL:
<?php
$x = "Hello world!";
$x = null;
var_dump($x);
?>

PHP Resourcehttp://www.javatraininginjaipur.online/