PHP几个数学计算的内部函数学习整理_php技巧
round
round - 对浮点数进行四舍五入。round 函数语法如下：
round(float,precision)
其中参数 precision 表示小数点后面要保持的精度位数。如果不写参数 precision，表示四舍五入到整数位，比如：
echo round(3.4); // 3echo round(3.5); // 4echo round(3.6); // 4
如果 precision 为2，表示四舍五入到小数点后2位。示例如下：
echo round(1.95583, 2); // 1.96
如果参数 precision 为负数，表示四舍五入到小数点前。比如：
echo round(1241757, -3); // 1242000
floor
floor - 舍去法求整。floor 函数语法如下：
floor (value)
floor 函数返回不大于 value 的最大整数，即将 value 的小数部分舍去取整。示例如下：
echo floor(4); //4
echo floor(4.3); // 4echo floor(9.999); // 9
ceil
ceil - 进一法取整。ceil 函数语法如下：
ceil (value)
ceil 函数返回不小于 value 的最小整数。示例如下：
echo ceil(4); //4
echo ceil(4.3); // 5echo ceil(9.999); // 10
pow
pow - 求幂。pow 函数的语法如下：
pow (base,exp)
pow 函数返回 base 的 exp 次方的幂。下面的示例表示求 2 的8 次方，返回结果是256。
echo pow(2, 8); // 256
rand
rand - 产生一个随机整数。rand 函数语法如下：
rand (min,max)
rand 函数返回一个介于最小值 min 和最大值 max 之间 (包括min, max) 的随机整数。比如下面示例返回一个 2 到 6 之间的随机整数。
echo rand(2,6);
max
max - 返回参数中数值最大的值。
如果 max 函数只有一个参数且为数组，max 返回该数组中最大的值。
max 函数示例如下：
echo max(1, 3, 5, 6, 7); // 7echo max(array(2, 4, 5)); // 5
min
min - 返回参数中的最小值。
如果 min 函数只有一个参数且为数组，min 返回该数组中最小的值。
min 函数示例如下：
echo min(1, 3, 5, 6, 7); // 1echo min(array(2, 4, 5)); // 2
decbin
decbin - 十进制转换为二进制。decbin 函数语法如下：
decbin (number)
decbin 返回一个字符串，即返回参数 number 的二进制表示。示例如下：
echo decbin(12);
DE>decbin(12)DE> 返回的结果是：
1100
bindec
bindec - 二进制转换成十进制。bindec 函数语法如下：
bindec (binary_string)
bindec 函数将二进制字符串 binary_string 转换成一个十进制整数。示例如下：
echo bindec('110011'); //51
dechex, hexdec
dechex - 十进制转换为十六进制。
hexdec - 十六进制转换为十进制。
dechex, hexdec 函数示例如下：
echo dechex(47); //2f
echo hexdec('2f'); //47
decoct, octdec
decoct - 十进制转换为八进制
octdec - 八进制转换为十进制
decoct，octdec 函数示例如下：
echo decoct(12); //14
echo octdec('14'); //12
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
1664
14
1423
52
1318
25
1269
29
1248
24
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.
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 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.
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
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 vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
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.
