本文实例讲述了php判断数组中是否存在指定键(key)的方法。分享给大家供大家参考。具体分析如下:
php中有两个函数用来判断数组中是否包含指定的键,分别是array_key_exists和isset
array_key_exists语法如下
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array_key_exists ( $key , $array ) |
如果键存在返回true isset函数语法如下
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isset( $array [ $key ]) |
如果键存在返回true
演示代码如下:
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<?php $array = array ( "Zero" => "PHP" , "One" => "Perl" , "Two" => "Java" ); print ( "Is 'One' defined? " . array_key_exists ( "One" , $array ). "\n" ); print ( "Is '1' defined? " . array_key_exists ( "1" , $array ). "\n" ); print ( "Is 'Two' defined? " .isset( $array [ "Two" ]). "\n" ); print ( "Is '2' defined? " .isset( $array [2]). "\n" ); ?> |
返回结果如下:
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Is 'One' defined? 1 Is '1′ defined? Is 'Two' defined? 1 Is '2′ defined? |
希望本文所述对大家的php程序设计有所帮助。