What are the basic data types in php
The data types in PHP include strings, integers, floating point numbers, logic, arrays, objects, and NULL. Each type is explained below.
PHP String
A string is a sequence of characters, such as "Hello world!".
A string can be any text within quotes. You can use single or double quotes:
Example
<?php $x = "Hello world!"; echo $x; echo "<br>"; $x = 'Hello world!'; echo $x; ?>
PHP Integers
Integers are numbers without decimals.
Integer rules:
Integers must have at least one digit (0-9)
Integers cannot contain commas or spaces
Integers cannot have decimal points
Integers can be positive or negative
Integers can be specified in three formats: decimal, hexadecimal (prefix is 0x) or octal (prefix is 0)
In the following In the example, we will test different numbers. PHP var_dump() will return the data type and value of the variable:
Example
<?php $x = 5985; var_dump($x); echo "<br>"; $x = -345; // 负数 var_dump($x); echo "<br>"; $x = 0x8C; // 十六进制数 var_dump($x); echo "<br>"; $x = 047; // 八进制数 var_dump($x); ?>
PHP floating point number
Floating point number has decimal point or exponential form number.
In the example below we will test different numbers. PHP var_dump() will return the data type and value of the variable:
Instance
<?php $x = 10.365; var_dump($x); echo "<br>"; $x = 2.4e3; var_dump($x); echo "<br>"; $x = 8E-5; var_dump($x); ?>
PHP logic
The logic is true or false.
$x=true; $y=false;
Logic is often used for conditional testing. You'll learn more about conditional testing later in this tutorial.
PHP Array
Array stores multiple values in one variable.
In the following example, we will test different arrays. PHP var_dump() will return the data type and value of the variable:
Instance
<?php
$cars=array("Volvo","BMW","SAAB");
var_dump($cars);
?>PHP Object
The object is to store data and how to process the data The data type of the information.
In PHP, objects must be declared explicitly.
First we must declare the class of the object. For this we use the class keyword. A class is a structure containing properties and methods.
Then we define the data type in the object class and then use this data type in the instance of that class:
Instance
<?php
class Car
{
var $color;
function Car($color="green") {
$this->color = $color;
}
function what_color() {
return $this->color;
}
}
?>PHP NULL value
The special NULL value indicates that the variable has no value. NULL is the only possible value for the data type NULL.
The NULL value indicates whether the variable is empty. Also used to distinguish empty strings from null value databases.
You can clear the variable by setting the value to NULL:
实例 <?php $x="Hello world!"; $x=null; var_dump($x); ?>
The above is the detailed content of What are the basic data types in php. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
What data type should be used for gender field in MySQL database?
Mar 14, 2024 pm 01:21 PM
In a MySQL database, gender fields can usually be stored using the ENUM type. ENUM is an enumeration type that allows us to select one as the value of a field from a set of predefined values. ENUM is a good choice when representing a fixed and limited option like gender. Let's look at a specific code example: Suppose we have a table called "users" that contains user information, including gender. Now we want to create a field for gender, we can design the table structure like this: CRE
What is the best data type for gender fields in MySQL?
Mar 15, 2024 am 10:24 AM
In MySQL, the most suitable data type for gender fields is the ENUM enumeration type. The ENUM enumeration type is a data type that allows the definition of a set of possible values. The gender field is suitable for using the ENUM type because gender usually only has two values, namely male and female. Next, I will use specific code examples to show how to create a gender field in MySQL and use the ENUM enumeration type to store gender information. The following are the steps: First, create a table named users in MySQL, including
Mind map of Python syntax: in-depth understanding of code structure
Feb 21, 2024 am 09:00 AM
Python is widely used in a wide range of fields with its simple and easy-to-read syntax. It is crucial to master the basic structure of Python syntax, both to improve programming efficiency and to gain a deep understanding of how the code works. To this end, this article provides a comprehensive mind map detailing various aspects of Python syntax. Variables and Data Types Variables are containers used to store data in Python. The mind map shows common Python data types, including integers, floating point numbers, strings, Boolean values, and lists. Each data type has its own characteristics and operation methods. Operators Operators are used to perform various operations on data types. The mind map covers the different operator types in Python, such as arithmetic operators, ratio
Detailed explanation of how to use Boolean type in MySQL
Mar 15, 2024 am 11:45 AM
Detailed explanation of how to use Boolean types in MySQL MySQL is a commonly used relational database management system. In practical applications, it is often necessary to use Boolean types to represent logical true and false values. There are two representation methods of Boolean type in MySQL: TINYINT(1) and BOOL. This article will introduce in detail the use of Boolean types in MySQL, including the definition, assignment, query and modification of Boolean types, and explain it with specific code examples. 1. The Boolean type is defined in MySQL and can be
What is the best data type choice for gender field in MySQL?
Mar 14, 2024 pm 01:24 PM
When designing database tables, choosing the appropriate data type is very important for performance optimization and data storage efficiency. In the MySQL database, there is really no so-called best choice for the data type to store the gender field, because the gender field generally only has two values: male or female. But for efficiency and space saving, we can choose a suitable data type to store the gender field. In MySQL, the most commonly used data type to store gender fields is the enumeration type. An enumeration type is a data type that can limit the value of a field to a limited set.
Revealing the classification of basic data types in mainstream programming languages
Feb 18, 2024 pm 10:34 PM
Title: Basic Data Types Revealed: Understand the Classifications in Mainstream Programming Languages Text: In various programming languages, data types are a very important concept, which defines the different types of data that can be used in programs. For programmers, understanding the basic data types in mainstream programming languages is the first step in building a solid programming foundation. Currently, most major programming languages support some basic data types, which may vary between languages, but the main concepts are similar. These basic data types are usually divided into several categories, including integers
What are the basic knowledge necessary for learning Python?
Jan 13, 2024 pm 01:37 PM
What basic knowledge do you need to know before learning Python? With the continuous development of technologies such as artificial intelligence, big data and cloud computing, programming has become an increasingly important skill in modern society. As a simple, easy-to-learn and powerful programming language, Python is increasingly favored by programmers and beginners. If you also plan to learn Python, there are some basic knowledge that you must master before starting. Understand the basic concepts of programming. Before starting to learn any programming language, you first need to understand some basic concepts.
Introduction to basic syntax and data types of C language
Mar 18, 2024 pm 04:03 PM
C language is a widely used computer programming language that is efficient, flexible and powerful. To be proficient in programming in C language, you first need to understand its basic syntax and data types. This article will introduce the basic syntax and data types of C language and give examples. 1. Basic syntax 1.1 Comments In C language, comments can be used to explain the code to facilitate understanding and maintenance. Comments can be divided into single-line comments and multi-line comments. //This is a single-line comment/*This is a multi-line comment*/1.2 Keyword C language
