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:wampServerwwwApache服务器主目录practise例程.php:5:boolean true

D:wampServerwwwApache服务器主目录practise例程.php:7:boolean true

D:wampServerwwwApache服务器主目录practise例程.php:13:boolean true

D:wampServerwwwApache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:wampServerwwwApache服务器主目录practise例程.php:5:boolean true

D:wampServerwwwApache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:wampServerwwwApache服务器主目录practise例程.php:4:string 'JAVA' (length=4)

D:wampServerwwwApache服务器主目录practise例程.php:7:boolean false

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

D:wampServerwwwApache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 )