PHP Array 函数

在php教程中数组是种强大的数据类型，他可以做的事情很多，可以存储不同的数据类型在一个数组中，下面我们列出了数组常用的操作，排序，键名对数组排序等做法。

/* 数组的常用函数 * * 数组的排序函数 * sort() * rsort() * usort() * asort() * arsort() * uasort() * ksort() * krsort() * uksort() * uatsort() * natcasesort() * array_multisort() * * 1.简单的数组排序 * sort() rsort() * 2.根据键名对数组排序 * ksort() krsort() * 3.根据元素的值对数组排序 * asort() arsort() * 4.根据'自然数排序“法对数组排序 * natsort()//区分大小写字母比较 natcasescort()//不区分大小写字母的比较 * 5.根据用户自定义规则对数组排序 * usort() uasort() uksort()对键排序 * 6.对维数组的排序 * array_multisort() * * 拆分、合并、分解、接合的数组函数 * 1.array_slice() * 2.array_splice()//删除 * 3.array_combine()//合并 * 4.array_merge();//合并 * 5.array_intersect();//多个数组的交集 * 6.array_diff();//返回多个数组的差集 * * 数组与数据结构的函数 * 1.使用数组实现堆栈 //先进后出 * array_push() array_pop() * 2.使用数组实现队列 //先进先出 * array_unshift() array_shift() unset() * * * 其他与数组操作有关的函数 * array_rand() * shuffle() * array_sum() * range() */

//简单数组排序的使用$data=array(5,8,1,7,2);sort($data);//元素由小到大进行排序print_r($data);//Array ( [0] => 1 [1] => 2 [2] => 5 [3] => 7 [4] => 8 )rsort($data);//元素由大到小进行排序print_r($data);//Array ( [0] => 8 [1] => 7 [2] => 5 [3] => 2 [4] => 1 )

//根据键名排序的例子$data_2=array(5=>'five',8=>'eight',1=>'one',7=>'seven',2=>'two');ksort($data_2);//对数组的下标进行由小到大排序print_r($data_2);//Array ( [1] => one [2] => two [5] => five [7] => seven [8] => eight )krsort($data_2);//对数组的下标进行由大到小排序print_r($data_2);//Array ( [8] => eight [7] => seven [5] => five [2] => two [1] => one )

//根据元素的值对数组排序$data_3=array('1'=>'Linux','a'=>'Apache','m'=>'MySQL','l'=>'PHP');//asort() arsort 与 sort() rsort()的区别在于 前者排序后保持原有的键名,后者不保持原有键名，且键名从0开始asort($data_3);print_r($data_3);//Array ( [a] => Apache [1] => Linux [m] => MySQL [l] => PHP )echo ’’;arsort($data_3);print_r($data_3);//Array ( [l] => PHP [m] => MySQL [1] => Linux [a] => Apache )echo ’’;sort($data_3);print_r($data_3);//Array ( [0] => Apache [1] => Linux [2] => MySQL [3] => PHP )echo ’’;rsort($data_3);print_r($data_3);//Array ( [0] => PHP [1] => MySQL [2] => Linux [3] => Apache )

//根据”自然数排序法“对数组排序(0-9短者优先)$data_4=array('file.txt','file11.txt','file2.txt','file22.txt');sort($data_4);print_r($data_4);//Array ( [0] => file.txt [1] => file11.txt [2] => file2.txt [3] => file22.txt )echo ’’;natsort($data_4);print_r($data_4);//Array ( [0] => file.txt [2] => file2.txt [1] => file11.txt [3] => file22.txt )echo ’’;natcasesort($data_4);print_r($data_4);//Array ( [0] => file.txt [2] => file2.txt [1] => file11.txt [3] => file22.txt )echo ’’;

//用户自定义排序函数echo ’’;$data_5=array('Linux','Apache','MySQL','PHP');usort($data_5,'sortbylen');//通过元素长度排序print_r($data_5);//Array ( [0] => PHP [1] => MySQL [2] => Linux [3] => Apache )function sortbylen($one,$two){ if(strlen($one)==strlen($two)) return 0; else return (strlen($one)>strlen($two))?1:-1;}

//拆分、合并、分解、接合的数组函数echo ’’;$data_6=array('Linux','Apache','MySQL','PHP');print_r(array_slice($data_6,1,2));//取下标为1、2的元素//Array ( [0] => Apache [1] => MySQL ) 下标重置从0开始echo ’’;

print_r(array_slice($data_6,-2,1));//从后边的第二个开始取返回一个，不是从0开始的//Array ( [0] => MySQL ) 下标重置从0开始echo ’’;

print_r(array_slice($data_6,1,2,true));//Array ( [1] => Apache [2] => MySQL ) 保留原有的下标

echo ’’;

//array_combine()$a1=array('OS','WebServer','DataBase','Language');$a2=array('Linux','Apache','MySQL','PHP');

print_r(array_combine($a1,$a2));//第一个参数作为键名，第二个作为值来合并//Array ( [OS] => Linux [WebServer] => Apache [DataBase] => MySQL [Language] => PHP )

echo ’’;

//array_merge()$a3=array('OS','WebServer','DataBase','Language');$a4=array('Linux','Apache','MySQL','PHP');$a5=$a3+$a4;print_r($a5);//因为两个数组下标重复所以显示这样//Array ( [0] => OS [1] => WebServer [2] => DataBase [3] => Language )echo ’’;print_r(array_merge($a3,$a4));//合并并重新索引//Array ( [0] => OS [1] => WebServer [2] => DataBase [3] => Language [4] => Linux [5] => Apache [6] => MySQL [7] => PHP )

echo ’’;

//array_intersect()$a7=array('OS','WebServer','DataBase','Language',1,2,3);$a8=array('Linux','Apache','MySQL','PHP',2,3,4);print_r(array_intersect($a7,$a8));//Array ( [5] => 2 [6] => 3 )echo ’’;

//array_diff()$a9=array(1,2,3,4);$a10=array(3,4,5,6);print_r(array_diff($a9,$a10));//Array ( [0] => 1 [1] => 2 )//返回第一个数组跟第二个相差的元素echo ’’;

//使用数组实现堆栈$b=array(1,2,3,4);$b[]='a';//入栈array_push($b,'b','c');//使用函数入栈print_r($b);//Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => a [5] => b [6] => c )echo ’’;

$value=array_pop($b);//使用函数出栈print_r($b);//Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => a [5] => b )echo ’’;echo $value;//显示出栈的元素的值 cecho ’’;

//使用数组实现队列$c=array(1,2,3);print_r($c);//Array ( [0] => 1 [1] => 2 [2] => 3 )echo ’’;array_unshift($c,'abc','bcd');//入队print_r($c);//Array ( [0] => abc [1] => bcd [2] => 1 [3] => 2 [4] => 3 )echo ’’;$values=array_shift($c);//出队print_r($c);// Array ( [0] => bcd [1] => 1 [2] => 2 [3] => 3 )echo ’’;unset($c[2]);//删除指定位置元素print_r($c);//Array ( [0] => bcd [1] => 1 [3] => 3 )echo ’’;

//array_rand() 随机返回数组下标$arr=array(1,3,4,5,76,7,99,6,2,3);echo array_rand($arr);//返回的是随机的数组元素的下标echo $arr[array_rand($arr)];//随机显示数组元素的值echo ’’;//shuffle() 随机重新排列数组$arr2=array(32,35,33);shuffle($arr2);print_r($arr2);//数组元素位置随机变换echo ’’;//array_sum() 求和$arr3=array(1,3,5);echo array_sum($arr3); //返回9echo ’’;print_r($arr3);//Array ( [0] => 1 [1] => 3 [2] => 5 )echo ’’;//range(最小值，最大值，步长)$arr4=range(0,100,10);print_r($arr4);//Array ( [0] => 0 [1] => 10 [2] => 20 [3] => 30 [4] => 40 [5] => 50 [6] => 60 [7] => 70 [8] => 80 [9] => 90 [10] => 100 )

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