array_splice

これはちょっとびっくり

<?php
$array1=array(  "果物"=>array("りんご","みかん","すいか","メロン"),
                                "お菓子"=>array("ポテチ","どら焼き","キャラメルコーン","羊羹"),
                                "ご飯"=>array("麦飯","白米","オートミール","ラーメン"),
                                "野菜"=>array("キャベツ","ピーマン","じゃがいも","白菜"),
                                "さかな"=>array("鯖","マグロ","イカ","鮭")
);
$array2=array(  "おかず"=>array("鯖缶","ツナ缶","野菜炒め","焼き魚"),
                                "サプリメント"=>array("ウィダー","プロティン","スポーツ羊羹")   );
$array3=array(  "豚肉"=>array("ブタコマ","タン","バラ","豚足"),
                                "鶏肉"=>array("胸肉","チキンカツ","手羽先","ナンコツ")  );
$i=0;
foreach($array1 as $key =>$value){
        $i++;
        if(     $key=="お菓子"  ){
                array_splice($array1,$i,0,$array2);
        }
        if(     $key=="ご飯"    ){
                array_splice($array1,$i,0,$array3);
        }
        print $key."\n";
        var_dump($value);
}
print_r($array1);
?>