What is object data type in php?

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Description
PHP: Tips of the Day
PHP Data Types
PHP Integer
PHP Boolean
PHP NULL Value
PHP Resource
What is object data type?
What are objects in PHP?
How do I declare an object in PHP?
What is the difference between object and data type?

Last update on August 19 2022 21:50:39 (UTC/GMT +8 hours)

Description

An object is a data type which stores not only data but also information on how to process that data. Unlike the other data types in PHP, an object must be explicitly declared.

At first, we must declare a class of object. A class is a structure which contains properties and methods.

Classes are defined with the class keyword. We define the data type in the object class, and then we use the data type in instances of that class.

Example:

<?php class student
{
function marks_calculation()
{         
echo "Display marks";
}
}
$student1 = new student;
$student1->marks_calculation(); 
?>

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PHP: Tips of the Day

PHP: Pass a PHP string to a JavaScript variable (and escape newlines)

<script>
  var myvar = <?php echo json_encode($myVarValue); ?>;
</script>

Using json_encode() requires:

PHP 5.2.0 or greater
$myVarValue encoded as UTF-8 (or US-ASCII, of course)

Since UTF-8 supports full Unicode, it should be safe to convert on the fly.

Note that because json_encode escapes forward slashes, even a string that contains </script> will be escaped safely for printing with a script block.

Ref : https://bit.ly/34f0Dym

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PHP Data Types

Variables can store data of different types, and different data types can do different things.

PHP supports the following data types:

String
Integer
Float (floating point numbers - also called double)
Boolean
Array
Object
NULL
Resource

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:

Example

<?php
$x = "Hello world!";
$y = 'Hello world!';

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

Try it Yourself »

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: decimal (base 10), hexadecimal (base 16), octal (base 8), or binary (base 2) notation

In the following example $x is an integer. The PHP var_dump() function returns the data type and value:

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 Boolean

A Boolean represents two possible states: TRUE or FALSE.

Booleans are often used in conditional testing. You will learn more about conditional testing in a later chapter of this tutorial.

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:

Example

<?php
$cars = array("Volvo","BMW","Toyota");
var_dump($cars);
?>

Try it Yourself »

You will learn a lot more about arrays in later chapters of this tutorial.

PHP Object

Classes and objects are the two main aspects of object-oriented programming.

A class is a template for objects, and an object is an instance of a class.

When the individual objects are created, they inherit all the properties and behaviors from the class, but each object will have different values for the properties.

Let's assume we have a class named Car. A Car can have properties like model, color, etc. We can define variables like $model, $color, and so on, to hold the values of these properties.

When the individual objects (Volvo, BMW, Toyota, etc.) are created, they inherit all the properties and behaviors from the class, but each object will have different values for the properties.

If you create a __construct() function, PHP will automatically call this function when you create an object from a class.

Example

<?php
class Car {
public $color;
public $model;
public function __construct($color, $model) {
    $this->color = $color;
    $this->model = $model;
}
public function message() {
    return "My car is a " . $this->color . " " . $this->model . "!";
}
}

$myCar = new Car("black", "Volvo");
echo $myCar -> message();
echo "<br>";
$myCar = new Car("red", "Toyota");
echo $myCar -> message();
?>

Try it Yourself »

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 Resource

The special resource type is not an actual data type. It is the storing of a reference to functions and resources external to PHP.

A common example of using the resource data type is a database call.

We will not talk about the resource type here, since it is an advanced topic.

What is object data type?

The Object data type can point to data of any data type, including any object instance your application recognizes. Use Object when you do not know at compile time what data type the variable might point to. The default value of Object is Nothing (a null reference).

What are objects in PHP?

An Object is an individual instance of the data structure defined by a class. We define a class once and then make many objects that belong to it. Objects are also known as instances.

How do I declare an object in PHP?

If an object is converted to an object, it is not modified. If a value of any other type is converted to an object, a new instance of the stdClass built-in class is created. and here (starting with PHP 7.3. 0, var_export() exports an object casting an array with (object) ):

What is the difference between object and data type?

srikarvedantam. A 'data-type' is a type of data such as an integer, a boolean, or a character. It defines what values a variable of a 'data-type' can hold and what operations can be performed on it. An object is an instance of a class.

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