6.5.5 PHP數(shù)組中統(tǒng)計(jì)數(shù)組元素的個(gè)數(shù)與唯一性的函數(shù)

統(tǒng)計(jì)數(shù)組元素的個(gè)數(shù)與唯一性
count -- 計(jì)算數(shù)組中的單元數(shù)目或?qū)ο笾械膶傩詡€(gè)數(shù)
語(yǔ)法：int count ( mixed var [, int mode] )
如果可選的 mode 參數(shù)設(shè)為 COUNT_RECURSIVE（或 1），count() 將遞歸地對(duì)數(shù)組計(jì)數(shù)。
array_count_values -- 統(tǒng)計(jì)數(shù)組中所有的值出現(xiàn)的次數(shù)
語(yǔ)法：array array_count_values ( array input )
array_unique -- 移除數(shù)組中重復(fù)的值
語(yǔ)法：array array_unique ( array array )

例1.php

<?php

    $lamp = array("os"=>"Linux", "webserver"=>"Apache","db"=>"MySQL", "language"=>"PHP");

    
    print_r($lamp);
    echo '<br>';


    $str = "";

    var_dump(count($str));   //strlen();

例2.php

<?php

/*  $lamp = array("os"=>"Linux", "webserver"=>"Apache","db"=>"MySQL", "language"=>"PHP");

    
    print_r($lamp);
    echo '<br>';

 */

    $web = array(
            "lamp"=>array("os"=>"Linux", "webserver"=>"Apache","db"=>"MySQL", "language"=>"PHP"),
            "JavaEE" => array("os"=>"Unix", "webserver"=>"Tomcat","db"=>"Oracle", "language"=>"JSP")
        
        );


    echo count($web, 1);

例 3 test.php

<?php

//  $lamp = array("os"=>"Linux", "webserver"=>"Apache","db"=>"MySQL", "language"=>"PHP");

    
    print_r($lamp);
    echo '<br>';