String operation functions_PHP tutorial
There are many string manipulation functions in PHP3.0, the important ones are the following:
(1)echo,print,printf,sprintf
Used to output a string. If there is a variable name in the string, it will be replaced by its value. The latter two functions are similar to the C functions of the same name.
(2)strchr, strlen, strtok, strrchr, strrev, strstr, strtolower, strtoupper, substr, ucfirst
Some of the string manipulation functions used have exactly the same meaning as the functions of the same name in C. strrev is to flip a string. strtolower and strtoupper are to convert the string into lowercase and uppercase. ucfirst is to change the first character of the string into into uppercase. substr is a substring of the returned string. The usage is: substr (string, head, length). The head position is calculated from 0. If it is a negative number, it means counting forward from the tail.
(3)Chr,Ord
Function with the same name.
(4)explode,implode,join
Functions related to arrays. explode(string, separator) returns an array generated by dividing the string at the separator. implode(array, separator) returns an array formed by inserting separators between each element of the array. string. join has the same meaning as implode.
(5)Chop
Handle whitespace at the end of the string.
(6)htmlspecialchars
Replace HTML special characters with their names, for example "<" becomes "<".
(7)nl2br
Add "
before each carriage return in HTML
".
(8)AddSlashes,StripSlashes
Add "" and remove "" to the string as needed. For some databases, you must add or remove "" from the characters to be queried before you can query.
(9)parse_str
Analyze strings of type "name1=value1&name2=value2&..." into some variables.
For example: parse_str("a=1&b=2"); generates two variables $a and $b, with values 1 and 2 respectively. If there are two pairs of names/values with the same name part, the value of the latter one will overwrite the previous one. . If the names of these two pairs have "[]" at the end, such as "a[]=1&a[]=2", then an array $a will be generated, with the two elements being 1 and 2 respectively.

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



Go language provides two dynamic function creation technologies: closure and reflection. closures allow access to variables within the closure scope, and reflection can create new functions using the FuncOf function. These technologies are useful in customizing HTTP routers, implementing highly customizable systems, and building pluggable components.

In C++ function naming, it is crucial to consider parameter order to improve readability, reduce errors, and facilitate refactoring. Common parameter order conventions include: action-object, object-action, semantic meaning, and standard library compliance. The optimal order depends on the purpose of the function, parameter types, potential confusion, and language conventions.

The key to writing efficient and maintainable Java functions is: keep it simple. Use meaningful naming. Handle special situations. Use appropriate visibility.

The advantages of default parameters in C++ functions include simplifying calls, enhancing readability, and avoiding errors. The disadvantages are limited flexibility and naming restrictions. Advantages of variadic parameters include unlimited flexibility and dynamic binding. Disadvantages include greater complexity, implicit type conversions, and difficulty in debugging.

1. The SUM function is used to sum the numbers in a column or a group of cells, for example: =SUM(A1:J10). 2. The AVERAGE function is used to calculate the average of the numbers in a column or a group of cells, for example: =AVERAGE(A1:A10). 3. COUNT function, used to count the number of numbers or text in a column or a group of cells, for example: =COUNT(A1:A10) 4. IF function, used to make logical judgments based on specified conditions and return the corresponding result.

What is GateToken(GT) currency? GT (GateToken) is the native asset on the GateChain chain and the official platform currency of Gate.io. The value of GT coins is closely related to the development of Gate.io and GateChain ecology. What is GateChain? GateChain was born in 2018 and is a new generation of high-performance public chain launched by Gate.io. GateChain focuses on protecting the security of users' on-chain assets and providing convenient decentralized transaction services. GateChain's goal is to build an enterprise-level secure and efficient decentralized digital asset storage, distribution and transaction ecosystem. Gatechain has original

Exception handling in C++ can be enhanced through custom exception classes that provide specific error messages, contextual information, and perform custom actions based on the error type. Define an exception class inherited from std::exception to provide specific error information. Use the throw keyword to throw a custom exception. Use dynamic_cast in a try-catch block to convert the caught exception to a custom exception type. In the actual case, the open_file function throws a FileNotFoundException exception. Catching and handling the exception can provide a more specific error message.

The difference between custom PHP functions and predefined functions is: Scope: Custom functions are limited to the scope of their definition, while predefined functions are accessible throughout the script. How to define: Custom functions are defined using the function keyword, while predefined functions are defined by the PHP kernel. Parameter passing: Custom functions receive parameters, while predefined functions may not require parameters. Extensibility: Custom functions can be created as needed, while predefined functions are built-in and cannot be modified.
