This article introduces the use of the most basic loop statements, including the most basic statements such as for(), while(), foreach() do while in php.
while loop
The while loop is the simplest loop in PHP, its basic format is:
The code is as follows
Copy code
while (expr){
代码如下
复制代码
while (expr){
statement
}
//或者
while (expr):
statement
endwhile;
Statement
}
//or
while (expr):
Statement
代码如下
复制代码
$i = 1;
while ($i <= 10) {
echo $i;
$i++;
}
?>
endwhile;
This syntax means that as long as the expr expression is TRUE, the statement will be executed until expr is FALSE. The statement represents the action or logic to be executed.
Example:
The code is as follows
Copy code
$i = 1;
while ($i <= 10) {
代码如下
复制代码
do {
statement
}while (expr)
echo $i;
$i++;
}
代码如下
复制代码
$i = 1;
do {
echo $i;
$i++;
} while ($i <= 10);
?>
?>
This example loops out 1 to 10.
do-while loop
The do-while loop is very similar to the while loop, the only difference is that do-while is guaranteed to be executed once, while while may not do anything when the expression does not hold.
代码如下
复制代码
for (expr1; expr2; expr3){
statement
}
The do-while loop has only one syntax:
The code is as follows
Copy code
do {
代码如下
复制代码
for ($i = 1; $i <= 10; $i++) {
echo $i;
}
?>
statement
}while (expr)
Example:
The code is as follows
Copy code
$i = 1;<🎜>
do {<🎜>
echo $i;<🎜>
$i++;<🎜>
} while ($i <= 10);<🎜>
?>
This example also outputs 1 to 10
for loop
The for loop is a more complex loop in PHP. Its syntax is as follows:
Grammar interpretation
The first expression (expr1) is evaluated unconditionally once before the loop starts
expr2 is evaluated before each loop starts. If the value is TRUE, the loop continues and the nested loop statement is executed; if the value is FALSE, the loop is terminated.
expr3 is evaluated (executed) after each loop
Every expression can be null. If expr2 is empty, the loop will continue indefinitely, but the loop can be ended by break:
The code is as follows
break;
}
echo $i;
}
?>
Tips
When using loop statements, we usually have to be careful not to loop endlessly and cause the program to "zombie". In addition, we must also pay attention to the loop conditions (loop judgment expressions) to ensure that the loop results are correct.
http://www.bkjia.com/PHPjc/629220.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/629220.htmlTechArticleThis article introduces the use of the most basic loop statements, including for(), while(), foreach() do while are the most basic statements. while loop while loop is the simplest loop in PHP...
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals.
This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati
CakePHP is an open-source framework for PHP. It is intended to make developing, deploying and maintaining applications much easier. CakePHP is based on a MVC-like architecture that is both powerful and easy to grasp. Models, Views, and Controllers gu
Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems.
With a large collection of extensions for many programming languages, VS Code can be c
This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an
CakePHP is an open source MVC framework. It makes developing, deploying and maintaining applications much easier. CakePHP has a number of libraries to reduce the overload of most common tasks.
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase.
What is a vowel?
Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase:
a, e, i, o, u
Example 1
Input: String = "Tutorialspoint"
Output: 6
explain
The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
Backend Development
