Common math built-in functions in PHP:
1. Function: abs()
Function: take the absolute value
For example:
<?php
echo abs(-21.2); // 当数字为 负数时
echo abs(21.2); // 当数字为 正数时
<?
result:
2. Function: max()
Function: Get the largest number in a set of numbers
For example:
<?php
echo max(2,4,5,-6,99); // max() 函数的实例
?>
result:
3. Function: min()
Function: Take out the smallest number in a set of numbers
For example:
<?php
echo min(2,4,5,-6,99); // min() 函数的实例
?>
result:
4. Function: ceil()
Function: round up
For example:
<?php
echo ceil(12.2) // 当小数点后为 小于 5 时
echo ceil(0) // 当为0 时
echo ceil(12.9) // 当小数点后为 大于于 5 时
?>
result:
5. Function: floor()
Function: round down
For example:
<?php
echo floor(12.2) // 当小数点后为 小于 5 时
echo floor(0) // 当为0 时
echo floor(12.9) // 当小数点后为 大于于 5 时
?>
result:
6. Function: round()
Function: round floating point numbers
For example:
<?php
echo round(12.2) // 当小数点后为 小于 5 时
echo round(12) // 当为整数 时
echo round(12.9) // 当小数点后为 大于于 5 时
?>
result:
7. Function: rand()
Role: Generate random numbers
For example:
<?php
echo rand(1,3) // 范围是在 1 ~ 3
echo rand(-7,3) // 范围是在 -7 ~ 3
echo rand(0.9999999999999999999) // 范围是在 0 ~ 99999999999999999
echo rand() // 随机产生数字
?>
result:
Note: The random number generation function rand(), the numbers generated are all integers (int), and the maximum number of positive integers it can generate is "9999999999999999999999" (that is, '20' '9').