国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Home Backend Development PHP Tutorial Commonly used string processing functions in php

Commonly used string processing functions in php

Jul 25, 2016 am 08:45 AM

1Find character position function:
strpos($str,$seach,[int]); Find the first position of search in $str starting from int;
stripos($str,$seach,[int]); The function returns the position of the first occurrence of a string in another string. This function is not case sensitive
strrpos($str,search,[int]): Find the last occurrence of search in $str starting from int
strripos($str,search,[int]): Same as above, this function is not case sensitive


2. Function to extract substrings
substr($str,int start,[int len])
strstr($str1,str2)
stristr() has the same function as strstr, except that it is not case sensitive
strrchr() returns from the last character searched; use: to get the file name in the path


3. PHP string function to replace string
str_replace(search,replace,source) finds search and replaces it in source
str_ireplace(search,replace,$str): Same as above, this function is not case sensitive
strtr ($str, $from, $to) This function returns a copy of str and converts the characters specified in from to the corresponding characters in to
$trans = array("hello" => "hi", "hi" => "hello");
echo strtr("hi all, I said hello", $trans);
?>
substr_replace($Str,$rep,$start[,length]): $str original string, $rep new string after replacement, $start starting position, $length replacement length, this item is optional


4. Character length
int strlen($str)


5. Compare character function
int strcmp($str1,$str2)$str1>= strcasecmp() ignores case (same as above)
strnatcmp("8","18") compares strings in natural order
strnatcasecmp()


6. PHP string function split into arrays
str_split($str,len)
split(search,$str,[int])
explode(search,$str,[int]) splits $str according to the search characters and returns the array int. How many times will it be split? The rest will not be split.


7. Remove spaces:
ltrim() rtrim() trim()


8. Add space function
chunk_split($str,2) press 2 characters into the $str character to add a space;


9. chr, ord--return the specified character or ascii


10. Functions related to html code
nl2br() converts n into

strip_tags($str,['

']) removes HTML and PHP tags
Such as: echo strip_tags($text, '

')
htmlspecialchars($str[,var])


11. PHP string function for character case conversion
strolower(str)
stroupper(str)
ucfirst(str) converts the first character of the function to uppercase
ucwords(str) converts the first letter of each word to uppercase


12. Database-related PHP string functions
addslashes(str) converts single quotes ('), double quotes ("), backslashes () and NUL strings in str to ',",\.
magic_quotes_gpc = On: Automatically escape the contents of get, post, and cookie
get_magic_quotes_gpc(): Check whether magic_quotes_gpc is turned on
stripslashes(): Remove backslashes from strings

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

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How do I implement authentication and authorization in PHP? How do I implement authentication and authorization in PHP? Jun 20, 2025 am 01:03 AM

TosecurelyhandleauthenticationandauthorizationinPHP,followthesesteps:1.Alwayshashpasswordswithpassword_hash()andverifyusingpassword_verify(),usepreparedstatementstopreventSQLinjection,andstoreuserdatain$_SESSIONafterlogin.2.Implementrole-basedaccessc

How can you handle file uploads securely in PHP? How can you handle file uploads securely in PHP? Jun 19, 2025 am 01:05 AM

To safely handle file uploads in PHP, the core is to verify file types, rename files, and restrict permissions. 1. Use finfo_file() to check the real MIME type, and only specific types such as image/jpeg are allowed; 2. Use uniqid() to generate random file names and store them in non-Web root directory; 3. Limit file size through php.ini and HTML forms, and set directory permissions to 0755; 4. Use ClamAV to scan malware to enhance security. These steps effectively prevent security vulnerabilities and ensure that the file upload process is safe and reliable.

What are the differences between == (loose comparison) and === (strict comparison) in PHP? What are the differences between == (loose comparison) and === (strict comparison) in PHP? Jun 19, 2025 am 01:07 AM

In PHP, the main difference between == and == is the strictness of type checking. ==Type conversion will be performed before comparison, for example, 5=="5" returns true, and ===Request that the value and type are the same before true will be returned, for example, 5==="5" returns false. In usage scenarios, === is more secure and should be used first, and == is only used when type conversion is required.

How do I perform arithmetic operations in PHP ( , -, *, /, %)? How do I perform arithmetic operations in PHP ( , -, *, /, %)? Jun 19, 2025 pm 05:13 PM

The methods of using basic mathematical operations in PHP are as follows: 1. Addition signs support integers and floating-point numbers, and can also be used for variables. String numbers will be automatically converted but not recommended to dependencies; 2. Subtraction signs use - signs, variables are the same, and type conversion is also applicable; 3. Multiplication signs use * signs, which are suitable for numbers and similar strings; 4. Division uses / signs, which need to avoid dividing by zero, and note that the result may be floating-point numbers; 5. Taking the modulus signs can be used to judge odd and even numbers, and when processing negative numbers, the remainder signs are consistent with the dividend. The key to using these operators correctly is to ensure that the data types are clear and the boundary situation is handled well.

How can you interact with NoSQL databases (e.g., MongoDB, Redis) from PHP? How can you interact with NoSQL databases (e.g., MongoDB, Redis) from PHP? Jun 19, 2025 am 01:07 AM

Yes, PHP can interact with NoSQL databases like MongoDB and Redis through specific extensions or libraries. First, use the MongoDBPHP driver (installed through PECL or Composer) to create client instances and operate databases and collections, supporting insertion, query, aggregation and other operations; second, use the Predis library or phpredis extension to connect to Redis, perform key-value settings and acquisitions, and recommend phpredis for high-performance scenarios, while Predis is convenient for rapid deployment; both are suitable for production environments and are well-documented.

How do I stay up-to-date with the latest PHP developments and best practices? How do I stay up-to-date with the latest PHP developments and best practices? Jun 23, 2025 am 12:56 AM

TostaycurrentwithPHPdevelopmentsandbestpractices,followkeynewssourceslikePHP.netandPHPWeekly,engagewithcommunitiesonforumsandconferences,keeptoolingupdatedandgraduallyadoptnewfeatures,andreadorcontributetoopensourceprojects.First,followreliablesource

What is PHP, and why is it used for web development? What is PHP, and why is it used for web development? Jun 23, 2025 am 12:55 AM

PHPbecamepopularforwebdevelopmentduetoitseaseoflearning,seamlessintegrationwithHTML,widespreadhostingsupport,andalargeecosystemincludingframeworkslikeLaravelandCMSplatformslikeWordPress.Itexcelsinhandlingformsubmissions,managingusersessions,interacti

How to set PHP time zone? How to set PHP time zone? Jun 25, 2025 am 01:00 AM

TosettherighttimezoneinPHP,usedate_default_timezone_set()functionatthestartofyourscriptwithavalididentifiersuchas'America/New_York'.1.Usedate_default_timezone_set()beforeanydate/timefunctions.2.Alternatively,configurethephp.inifilebysettingdate.timez

See all articles