What are the php types?

PHP types include string, integer, floating point number, Boolean value, array, object and null. 1. Strings, including any characters, including letters, numbers, symbols, etc., can be connected, intercepted, replaced, etc.; 2. Integers, which can be represented by decimal, binary, octal or hexadecimal; 3. Floating point numbers , can be represented using standard floating point representation or scientific notation; 4. Boolean values, usually used for conditional judgment statements and logical operations; 5. Arrays, to contain different types of values, such as strings, integers, floating Points, etc.; 6. Objects, including data, etc.

The operating environment of this tutorial: The operating environment of this tutorial: windows10 system, php8.1.3 version, DELL G3 computer.

PHP is an open source server-side scripting language widely used in web development. It supports multiple data types, each with different characteristics and uses. This article will introduce common data types in PHP.

1. String (String): String is one of the most commonly used data types in PHP. It is composed of a series of characters and can be expressed using single or double quotes. Strings can contain any characters, including letters, numbers, symbols, etc. Strings can be concatenated, intercepted, replaced, etc.

For example:

$name = "John";
$email = 'john@example.com';
$message = "Hello, $name! Your email is $email.";

2. Integer (Integer): Integer is a number without decimal point. The integer type in PHP can represent positive integers, negative integers and zero. Integers can be represented in decimal, binary, octal, or hexadecimal notation.

For example:

$age = 25;
$quantity = -10;
$binary = 0b1011; // 二进制表示11
$octal = 0123; // 八进制表示83
$hexadecimal = 0x1A; // 十六进制表示26

3. Floating point number (Float): Floating point number is a number with a decimal point. It can be positive, negative and zero. In PHP, floating point numbers can be represented using standard floating point notation (e.g. 1.234) or scientific notation (e.g. 1.2e3).

例如：
$weight = 68.5;
$temperature = -17.8;
$scientificNotation = 6.02e23; // 6.02乘以10的23次方

4. Boolean: Boolean represents true or false. It has only two values: true (true) and false (false). In PHP, Boolean values ​​are usually used in conditional statements and logical operations.

For example:

$isOldEnough = true;
$isWorking = false;

5. Array (Array): An array is an ordered collection used to store multiple values. Each element in the array has a unique key through which the values ​​in the array can be accessed and manipulated. Arrays can contain values ​​of different types, such as strings, integers, floating point numbers, etc.

For example:

$fruits = array("apple", "banana", "orange");
$student = array("name" => "John", "age" => 25, "grade" => "A");

6. Object (Object): An object is an instance based on a class, which contains data attributes and methods. Objects are used in PHP to implement object-oriented programming (OOP). The process of creating an object is called instantiation.

For example:

class Car {
public $brand;
public function startEngine() {
echo "Engine started.";
}
}
$myCar = new Car();
$myCar->brand = "Toyota";
$myCar->startEngine();

7. Empty (NULL): A null value means that the variable has no value. In PHP, if a variable is not assigned a value or is explicitly assigned a value of null, its value is null. The null value is often used when determining whether a variable has a value.

For example:

$city = null;
if ($city === null) {
echo "City is not defined.";
}

In addition to the above basic data types, PHP also provides some other special data types, such as resources (Resource) and callback (Callback), etc., for specific scenarios and function.

To summarize, common data types in PHP include strings, integers, floating point numbers, Boolean values, arrays, objects and null values. Understanding and being familiar with these data types is very important for developing PHP applications, so that you can better process data and implement various functions. .

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