5_PHP数组_3_数组处理函数及其应用_7_数组排列函数

以下为学习孔祥盛主编的《PHP编程基础与实例教程》（第二版）所做的笔记。

数组排列函数

1. sort() 函数

程序：

 <?php
 $array = array("img12.gif","img10.gif","img2.gif","img1.gif");
 sort($array);
 print_r($array);
 //Array ( [0] => img1.gif [1] => img10.gif [2] => img12.gif [3] => img2.gif )
 ?>

输出：

Array ( [0] => img1.gif [1] => img10.gif [2] => img12.gif [3] => img2.gif )

2. asort() 函数

程序：

 <?php
 $array = array("img12.gif","img10.gif","img2.gif","img1.gif");
 asort($array);
 print_r($array);
 //Array ( [3] => img1.gif [1] => img10.gif [0] => img12.gif [2] => img2.gif )
 ?>

输出：

Array ( [3] => img1.gif [1] => img10.gif [0] => img12.gif [2] => img2.gif )

3. rsort() 函数 和 arsort() 函数

程序：

 <?php
 $array1 = $array2 = array("img12.gif","img10.gif","img2.gif","img1.gif");
 rsort($array1);
 print_r($array1);
 //Array ( [0] => img2.gif [1] => img12.gif [2] => img10.gif [3] => img1.gif )
 echo "<br/>";
 arsort($array2);
 print_r($array2);
 //Array ( [2] => img2.gif [0] => img12.gif [1] => img10.gif [3] => img1.gif )
 ?>

输出：

Array ( [0] => img2.gif [1] => img12.gif [2] => img10.gif [3] => img1.gif )
Array ( [2] => img2.gif [0] => img12.gif [1] => img10.gif [3] => img1.gif )

4. ksort() 函数

程序：

 <?php
 $array1 = array( "c"=>"China","f"=>"French","e"=>"English" );
 ksort($array1);
 print_r($array1);
 //Array ( [c] => China [e] => English [f] => French )
 ?>

输出：

Array ( [c] => China [e] => English [f] => French )

5. krsort() 函数

程序：

 <?php
 $array1 = array( "c"=>"China","f"=>"French","e"=>"English" );
 krsort($array1);
 print_r($array1);
 //Array ( [f] => French [e] => English [c] => China )
 ?>

输出：

Array ( [f] => French [e] => English [c] => China )

6. natsort() 函数

程序：

 <?php
 $array = array("A12","a10","a2","A1");
 natsort($array);　　//区分大小写
 print_r($array);
 //Array ( [3] => A1 [0] => A12 [2] => a2 [1] => a10 )
 ?>

输出：

Array ( [3] => A1 [0] => A12 [2] => a2 [1] => a10 )

7. natcasesort() 函数

程序：

 <?php
 $array = array("A12","a10","a2","A1");
 natcasesort($array);    //不区分大小写
 print_r($array);
 //Array ( [3] => A1 [2] => a2 [1] => a10 [0] => A12 )
 ?>

输出：

Array ( [3] => A1 [2] => a2 [1] => a10 [0] => A12 )

8. shuffle() 函数

程序：

 <?php
 $array = array("A12","a10","a2","A1");
 shuffle($array);
 print_r($array);    //Array ( [0] => a10 [1] => a2 [2] => A1 [3] => A12 )
 echo "<br/>";
 shuffle($array);
 print_r($array);    //Array ( [0] => A1 [1] => a10 [2] => a2 [3] => A12 )
 echo "<br/>";
 ?>

输出：

Array ( [0] => a10 [1] => a2 [2] => A1 [3] => A12 )
Array ( [0] => A1 [1] => a10 [2] => a2 [3] => A12 ) 

9. array_reverse() 函数

程序：

 <?php
 $array = array("a12","a1","a2","a10");
 $newArray1 = array_reverse($array);
 print_r($newArray1);    //Array ( [0] => a10 [1] => a2 [2] => a1 [3] => a12 )
 echo "<br/>";
 $newArray2 = array_reverse($array,TRUE);
 print_r($newArray2);    //Array ( [3] => a10 [2] => a2 [1] => a1 [0] => a12 )
 echo "<br/>";
 ?>

输出：

Array ( [0] => a10 [1] => a2 [2] => a1 [3] => a12 )
Array ( [3] => a10 [2] => a2 [1] => a1 [0] => a12 )