sort(); 升序
对数组排序；
1 1 <?php 2 2 3 3 $fruits = array( "lemon" , "orange" , "banana" , "apple" ); 4 4 sort ( $fruits ); 5 5 foreach ( $fruits as $key => $val ) { 6 6 echo "fruits[" . $key . "] = " . $val . "\n" ; 7 7 } 8 8 9 9 ?> 10 10 //输出结果 11 11 12 12 fruits[0] = apple 13 13 fruits[1] = banana 14 14 fruits[2] = lemon 15 15 fruits[3] = orange
rsort();降序
-对数组逆向排序
此函数为 array 中的元素赋与新的键名。这将删除原有的键名，而不是仅仅将键名重新排序。
<?php $fruits = array( "lemon" , "orange" , "banana" , "apple" ); rsort ( $fruits ); foreach ( $fruits as $key => $val ) { echo " $key = $val \n" ; } ?> //以上例程会输出： 0 = orange 1 = lemon 2 = banana 3 = apple
arsort();升序
对数组进行逆向排序并保持索引关系
1 <?php 2 $fruits = array( "d" => "lemon" , "a" => "orange" , "b" => "banana" , "c" => "apple" ); 3 arsort ( $fruits ); 4 foreach ( $fruits as $key => $val ) { 5 echo " $key = $val \n" ; 6 } 7 ?> 8 //以上例程会输出： 9 10 a = orange 11 d = lemon 12 b = banana 13 c = apple
asort();降序
对数组进行排序并保持索引关系；排值。
1 <?php 2 $fruits = array( "d" => "lemon" , "a" => "orange" , "b" => "banana" , "c" => "apple" ); 3 asort ( $fruits ); 4 foreach ( $fruits as $key => $val ) { 5 echo " $key = $val \n" ; 6 } 7 ?> 8 //以上例程会输出： 9 10 c = apple 11 b = banana 12 d = lemon 13 a = orange
ksort();升序
对数组按照键名排序。
1 <?php 2 $fruits = array( "d" => "lemon" , "a" => "orange" , "b" => "banana" , "c" => "apple" ); 3 ksort ( $fruits ); 4 foreach ( $fruits as $key => $val ) { 5 echo " $key = $val \n" ; 6 } 7 ?> 8 //以上例程会输出： 9 10 a = orange 11 b = banana 12 c = apple 13 d = lemon
krsort ();降序
对数组按照键名逆向排序
1 <?php 2 $fruits = array( "d" => "lemon" , "a" => "orange" , "b" => "banana" , "c" => "apple" ); 3 krsort ( $fruits ); 4 foreach ( $fruits as $key => $val ) { 5 echo " $key = $val \n" ; 6 } 7 ?> 8 //以上例程会输出： 9 10 d = lemon 11 c = apple 12 b = banana 13 a = orange
原文：http://www.cnblogs.com/sunshine-c/p/3748488.html