5_PHP数组_3_数组处理函数及其应用_6_数组检索函数

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。

数组检索函数

1. array_keys() 函数

程序：

 <?php
 $interests[2] = "music";
 $interests[5] = "movie";
 $interests[1] = "computer";
 $interests[] = "software";
 $interests[] = "computer";
 $keys = array_keys($interests);
 print_r($keys); //Array ( [0] => 2 [1] => 5 [2] => 1 [3] => 6 [4] => 7 )
 echo "<br/>";
 $searchKeys1 = array_keys($interests,"computer");
 print_r($searchKeys1);  //Array ( [0] => 1 [1] => 7 )
 echo "<br/>";
 $searchKeys2 = array_keys($interests,"Computer");
 print_r($searchKeys2);  //Array ( )
 //如果 searchValue 是字符串, 比较时区分大小写。
 ?>

输出：

Array ( [0] => 2 [1] => 5 [2] => 1 [3] => 6 [4] => 7 )
Array ( [0] => 1 [1] => 7 )
Array ( )

2. array_values() 函数

程序：

 <?php
 $interests[2] = "music";
 $interests[5] = "movie";
 $interests[1] = "computer";
 $interests[] = "software";
 $interests[] = "computer";
 $values = array_values($interests);
 print_r( $values );
 ?>

输出：

Array ( [0] => music [1] => movie [2] => computer [3] => software [4] => computer )

3. in_array() 函数

程序：

 <?php
 $words = array("JAVA","PHP",".NET");
 $javaExisted = in_array("JAVA",$words);
 $phpExisted = in_array("PHP",$words);
 var_dump($javaExisted);     //boolean true
 echo "<br/>";
 var_dump($phpExisted);      //boolean true
 echo "<br/>";

 $numbers = array('1.10',12.4,1.13);
 $numExisted1 = in_array(1.10,$numbers);
 $numExisted2 = in_array(1.10,$numbers,TRUE);  //会比较数据类型是否相同
 var_dump($numExisted1);     //boolean true
 echo "<br/>";
 var_dump($numExisted2);     //boolean false
 ?>

输出：

D:\wampServer\www\Apache服务器主目录\practise\例程.php:5:boolean true

D:\wampServer\www\Apache服务器主目录\practise\例程.php:7:boolean true

D:\wampServer\www\Apache服务器主目录\practise\例程.php:13:boolean true

D:\wampServer\www\Apache服务器主目录\practise\例程.php:15:boolean false

4. array_key_exists() 函数

程序：

 <?php
 $words = array( "SUN"=>"JAVA","Microsoft"=>".NET" );
 $keyExisted1 = array_key_exists("SUN",$words);
 $keyExisted2 = array_key_exists("sun",$words);
 var_dump($keyExisted1);     //boolean true
 echo "<br/>";
 var_dump($keyExisted2);     //boolean false
 ?>

输出：

D:\wampServer\www\Apache服务器主目录\practise\例程.php:5:boolean true

D:\wampServer\www\Apache服务器主目录\practise\例程.php:7:boolean false

5. array_search() 函数

程序：

 <?php
 $words = array(".NET"=>"Microsoft","JAVA"=>"SUN","JSP"=>"SUN");
 $searchKey1 = array_search("SUN",$words);
 var_dump($searchKey1);  //string 'JAVA' (length=4)
 echo "<br/>";
 $searchKey2 = array_search("microsoft", $words);
 var_dump($searchKey2);  //boolean false
 echo "<br/>";

 $numbers = array("PI"=>"3.14","直角"=>"90");
 $searchKey3 = array_search(90, $numbers);
 $searchKey4 = array_search(90, $numbers,TRUE);   //会比较数据类型是否相同
 var_dump($searchKey3);  //string '直角' (length=6)
 echo "<br/>";
 var_dump($searchKey4);  //boolean false
 ?>

输出：

D:\wampServer\www\Apache服务器主目录\practise\例程.php:4:string 'JAVA' (length=4)

D:\wampServer\www\Apache服务器主目录\practise\例程.php:7:boolean false

D:\wampServer\www\Apache服务器主目录\practise\例程.php:13:string '直角' (length=6)

D:\wampServer\www\Apache服务器主目录\practise\例程.php:15:boolean false

6. array_unique() 函数

程序：

 <?php
 $colors = array("a"=>"green","red","b"=>"green","blue","red");
 $colorUnique = array_unique($colors);   //Array ( [a] => green [0] => red [1] => blue )
 print_r($colorUnique);
 echo "<br/>";
 $input = array(4,"4","3",4,3,"3");
 $inputUnique = array_unique($input);    //Array ( [0] => 4 [2] => 3 )
 print_r($inputUnique);
 ?>

输出：

Array ( [a] => green [0] => red [1] => blue )
Array ( [0] => 4 [2] => 3 )