Basic php related functions
##1.join():
Definition and usagejoin() The function returns a string composed of array elements.
join() function is an alias of the implode() function.
Note:join() The function accepts two parameter orders. However, due to historical reasons, explode() does not work. You must ensure that the separator parameter comes before the string parameter.
Note:join() The separator parameter of the function is optional. However, for backward compatibility, it is recommended that you use two parameters.
Syntaxjoin(separator,array)
Parametersseparator:Optional,Specifies the content placed between array elements,The default is "" (empty string) or it can be "+","-"etc.
array:Required,An array to be combined into a string.
2.array_keys()
Definition and usage:
##array_keys()Function return A new array containing all the keys in the array. If the second parameter is provided, only the key name with the key value is returned.
For example:
<?php
$a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander");
print_r(array_keys($a));
?>
Running result:
Array ( [0] => Volvo [1] => BMW [2] => Toyota )
：Definition and usage:
array_values()The function returns an array containing the given array Array of all key values, but no key names. Tip: The returned array will use numeric keys, starting at
0and increasing by 1 . For example:
<?php
$a=array("Name"=>"Bill","Age"=>"60","Country"=>"USA");
print_r(array_values($a));
?>
Running result:
Array ( [0] => Bill [1] => 60 [2] => USA )
Function:
mysql_query()If there is a statement such as a query, it will return resources. To put it bluntly, it is the data result set you want to check; if there are statements such as additions, deletions, and modifications, it will return true or false. If you want to use this data result set, you must use
mysql_result(), mysql_fetch_array(), mysql_fetch_row()and other functions to obtain the data inside, which is mysql_query()Must be used in conjunction with the above functions.
5.mysql_fetch_assoc():mysql_fetch_assoc
will take out a row of records from the result set, and the resource pointer will jump down, In other words, when
mysql_fetch_assoc is used again, a new row of records will be obtained, 以此类推，每执行一次mysql_fetch_assoc，取一新行，直到取出最后一行， 再取时，因为已经没有下一行，就会返回false。 综上所述： 在你的第一个例子中， 是取出结果集的第一行，第一行不为空吧，所以$s_as不等于false，所以，当你用while($s_as)时，相当于while(true),是一个死循环,应该改成： 第二个例子中，则不同，while($s_as=mysql_fetch_assoc($s_re)),每次取一行，当取到最后一行时，再没有一下行了，mysql_fetch_assoc就会返回flash,也就是$s_as=false,while循环就会停止 处理字符串string。 start:规定再字符串的何处开始。 length：可选，规定被返回字符串的长度。默认是知道字符串的结尾。 用于遍历操作或输出数组，foreach() 仅能用于遍历数组或对象，当试图将其用于其它数据类型或者一个未初始化的变量时会产生错误. 语法： 上述语法中，每次循环将当前单元的值赋给 $value 并且数组内部的指针向前移一步。在第二种语法格式中还将当前单元的键名也会在每次循环中赋给变量 $key。 basename():获取文件路径的文件名. dirname():获取文件路径的目录 stripos(string,find,start) 定义和用法 stripos() 函数查找字符串在另一字符串中第一次出现的位置（不区分大小写）。 注释：stripos() 函数是不区分大小写的。 注释：该函数是二进制安全的 10.floor() Function :Round down to the nearest integer. 11.feof ( ) function: ##Function prototype: int feof(FILE * stream); Function description: 12.fscanf() The above is the detailed content of Basic php related functions. For more information, please follow other related articles on the PHP Chinese website!$s_as=mysql_fetch_assoc($s_re);
while($s_as)
$s_as = mysql_fetch_assoc($s_re);
while($s_as) {
$arr[] = $s_as;
$s_as = mysql_fetch_assoc($s_re); //你没写这行，所以$s_as永远不是false造成死循环。
}6.substr(string,start,length):
7.foreach():
foreach (array as $value)
statement
// 或者：
foreach (array as $key => $value)
statement
8.文件路径处理函数
9.字符串处理函数
is located in the header file: stdio.h
Return value: Returning a non-zero value means that the end of the file has been reached
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
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)
Hot Topics
1378
52
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian
Dec 24, 2024 pm 04:42 PM
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
How To Set Up Visual Studio Code (VS Code) for PHP Development
Dec 20, 2024 am 11:31 AM
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
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
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
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
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
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
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,
7 PHP Functions I Regret I Didn't Know Before
Nov 13, 2024 am 09:42 AM
If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
