Backend Development
PHP Tutorial
Pseudo-random number PHP random number generation code and usage example analysis
Pseudo-random number PHP random number generation code and usage example analysis
We can also use random numbers to design any program structure we can imagine.
First, let’s get to know the random number function rand() provided by PHP. PHP's rand() function will return a random integer. The specific usage is as follows
rand(min,max)
The optional parameters min and max can make rand() return a pseudo-random integer between 0 and RAND_MAX. For example, if you want a random number between 5 and 15 (inclusive), use rand(5, 15).
Let me look at a specific example below. We make a basic function call without setting specific parameters. The random number we get will not be limited by the min and max parameters.
Copy the code The code is as follows:
The result obtained: 652696728 (random result) 1. Use PHP to generate random numbers within the specified range If we want to generate a random number between two numbers, we need to set two parameters for rand: In this way, the result we get is under our control, it should be MinNum <= result <= MaxNum; Suppose we want to use PHP to generate random numbers between 10000 and 2000. Our code should be written like this:
Copy code The code is as follows:
echo(rand(1000,2000));?>
It’s simple enough, now let’s do something a little more difficult. At the beginning of this article, we said that random numbers are very useful. We can use PHP random numbers to solve some complex problems. 2. Use PHP to get a random element in a collection. Suppose we need to get a random element from an array
Copy the code The code is as follows:
$my_array=array('ASP','PHP', 'JAVASCRIPT','AJAX','CSS','JQUERY','HTML');
echo($my_array[rand(0,6)]);
?>
As you can imagine, the results we got It may be any element contained in the array such as ASP, PHP or JavaScript. Note that our my_array array contains seven elements, and we set the argument to rand() to be between 0 and 6. Next, we use two sets of random numbers to enhance the function of the above example. We need one random number for conditional judgment and another random number for the output of the element.
Copy the code The code is as follows:
$my_array=array('ASP','PHP','JAVASCRIPT','AJAX','CSS','JQUERY','HTML');
$ repetition=rand(0,6);
for($i=0;$i<=$repetition;$i++){
echo('I am learning ' . $my_array[rand(0,6)]);
echo(' on 51CTO.com');
}
?>
The results we get may look like the following:
The first time we run we get three results
Since we use a random The number limits the number of displayed items, so in addition to the random articles, the results are also random, as shown below:
The second run got seven results
Maybe you will ask, PHP random numbers only Can you do these boring things? rand() does not seem to be that important; you are wrong, think about the verification codes that can be seen everywhere, the random article extraction of some CMS systems, download address allocation, etc. Random numbers are used in these applications Play an important role; in addition, in the fields of security and algorithms, many applications of random numbers are also worthy of our in-depth study, such as encryption and congruence structures.
The above introduces the pseudo-random number PHP random number generation code and usage example analysis, including pseudo-random number content. I hope it will be helpful to friends who are interested in PHP tutorials.
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
1666
14
1425
52
1327
25
1273
29
1253
24
Explain secure password hashing in PHP (e.g., password_hash, password_verify). Why not use MD5 or SHA1?
Apr 17, 2025 am 12:06 AM
In PHP, password_hash and password_verify functions should be used to implement secure password hashing, and MD5 or SHA1 should not be used. 1) password_hash generates a hash containing salt values to enhance security. 2) Password_verify verify password and ensure security by comparing hash values. 3) MD5 and SHA1 are vulnerable and lack salt values, and are not suitable for modern password security.
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
How does PHP type hinting work, including scalar types, return types, union types, and nullable types?
Apr 17, 2025 am 12:25 AM
PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
