<?php
    //1.abs — 绝对值                  
    echo abs(-77);
 
    //ceil — 进一法取整               
    echo ceil(3.04);
    
    //floor  - 舍弃法取证             
    echo floor(3.14);
    
    //round -四舍五入取整             
    echo round(3.54);
    
    //max — 找出最大值
    $maxNum = max(1,2,3,4,5,11116,54,656,67,67);
    echo $maxNum;
    $maxNum = max(array(45,452345,1111111112345,45454,));
    echo $maxNum;
    
    //min --找出最小值
    $minNum = min(1,2,3,4,5,11116,54,656,67,67);
    echo $minNum;
    $minNum = min(array(45,452345,1111111112345,45454,));
    echo $minNum;
    
    //rand — 产生一个随机整数          
    echo rand(50,60);
    //生成更好的随机数                 
    echo mt_rand(50,60);
    
    //pi 得到圆周率值                  
    echo pi();
    //常量取圆周率                     
    echo M_PI;
    
    //sqrt  --  平方根                 
    echo sqrt(4);
    
    //pow  指数表达式                  
    echo pow(4,2);
    

?>

常用的math函数