PHP common functions
下面是我整理的PHP中常用的函数，有兴趣的小伙伴可以去看看。
array_intersect()
比较两个数组的键值，并返回交集：
<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"green","g"=>"blue");$result=array_intersect($a1,$a2);
print_r($result);
?>
result:Array ( [a] => red [b] => green [c] => blue )array_keys() 函数
返回包含数组中所有键名的一个新数组。
<?php
$a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander");
print_r(array_keys($a));
?>
result:Array ( [0] => Volvo [1] => BMW [2] => Toyota )123456array_key_exists() 函数
检查某个数组中是否存在指定的键名，如果键名存在则返回 true，如果键名不存在则返回 false。
<?php
$a=array("Volvo"=>"XC90","BMW"=>"X5"); if (array_key_exists("Volvo",$a))
{ echo "键存在！";
} else
{ echo "键不存在！";
}?>
result:键存在！12345678910111213array_merge() 函数
把两个数组合并为一个数组：
<?php
$a1=array("red","green");$a2=array("blue","yellow");
print_r(array_merge($a1,$a2));
?>
result:Array ( [0] => red [1] => green [2] => blue [3] => yellow )1234567array_reverse()
以相反的元素顺序返回数组：
<?php
$a=array("a"=>"Volvo","b"=>"BMW","c"=>"Toyota");
print_r(array_reverse($a));
?>
result:Array ( [c] => Toyota [b] => BMW [a] => Volvo )123456array_unshift() 函数
用于向数组插入新元素。新数组的值将被插入到数组的开头。
<?ph
$a=array("a"=>"red","b"=>"green");
array_unshift($a,"blue");
print_r($a);
?>
result:Array ( [0] => blue [a] => red [b] => green )1234567array_values
返回一个包含给定数组中所有键值的数组，但不保留键名。
<?php
$a=array("Name"=>"Bill","Age"=>"60","Country"=>"USA");
print_r(array_values($a));
?>
result:Array ( [0] => Bill [1] => 60 [2] => USA )123456hash_equals
可防止时序攻击的字符串比较
比较两个字符串，无论它们是否相等，本函数的时间消耗是恒定的。
本函数可以用在需要防止时序攻击的字符串比较场景中， 例如，可以用在比较 crypt() 密码哈希值的场景。
bool hash_equals ( string $known_string , string $user_string )1
参数：
known_string
已知长度的、要参与比较的 string
user_string
用户提供的字符串
返回值:
当两个字符串相等时返回 TRUE，否则返回 FALSE。
<?php$expected = crypt('12345', '$2a$07$usesomesillystringforsalt$'); $correct = crypt('12345', '$2a$07$usesomesillystringforsalt$'); $incorrect = crypt('apple', '$2a$07$usesomesillystringforsalt$'); var_dump(hash_equals($expected, $correct)); var_dump(hash_equals($expected, $incorrect)); ?> result: bool(true) bool(false)123456789101112
in_array() 函数
搜索数组中是否存在指定的值。
<?php$people = array("Bill", "Steve", "Mark", "David");if (in_array("Mark", $people))
{ echo "匹配已找到";
}else
{ echo "匹配未找到";
}
?>
result:匹配已找到1234567891011121314sprintf() 函数
把百分号（%）符号替换成一个作为参数进行传递的变量：
<?php
$number = 2;
$str = "Shanghai";
$txt = sprintf("There are %u million cars in %s.",$number,$str);
echo $txt;
?>
result:There are 2 million cars in Shanghai.12345678str_ireplace()
替换字符串中的一些字符（不区分大小写） str_ireplace(find,replace,string,count)
<?php
echo str_ireplace("WORLD","Shanghai","Hello world!");
?>
result:Hello Shanghai!12345strpos
查找字符串在另一字符串中第一次出现的位置。
<?php
echo strpos("You love php, I love php too!","php");
?>
result:912345str_replace()
以其他字符替换字符串中的一些字符（区分大小写）
<?php
echo str_replace("world","Shanghai","Hello world!");
?>
result:Hello Shanghai!12345str_ireplace()
替换字符串中的一些字符（不区分大小写）
str_ireplace(find,replace,string,count)
<?php
echo str_ireplace("WORLD","Shanghai","Hello world!");
?>
result:Hello Shanghai!12345substr
返回字符串的一部分。
<?php
echo substr("Hello world",6);
?>
result:world上面是我整理给大家的PHP常用函数，希望今后会对大家有帮助。
相关文章：
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
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)
Hot Topics
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
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
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
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,
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
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
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.
