"red","green"=>"green","white"=>"white","blue"=>"blue"); $color["black"]="black"; $color["red"]="#FF0000"; print_r($color); echo"
"; if(isset($color["green"])){ echo "我喜欢绿色"; } echo "
"; unset($color["green"]); if(!isset($color["green"])){ echo "我又不喜欢绿色"; } echo "
"; echo gettype($color["blue"]); echo "
"; var_dump($color["blue"]); ?>