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気づいたこと日記(1日目)

1# 配列の長さぶん処理をするときには
ForIn ではなく ForEach を使おう!
 
fruits.forEach(function(item, index, array) {
console.log(item, index);
});
// りんご 0
// バナナ 1
 

→indexも実は使える…

 for(let i in fruits){
console.log(fruits[i],i);
// りんご 0
// バナナ 1
/*
一見こっちの方が簡単にすませられそうだが、
*/
console.log(typeof i ,i+1);
// string,NaN
// string,NaN
/*
Indexが文字列なので計算できなかったり…
*/

}

なので、forinを使う

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