#author("2020-05-11T17:56:17+09:00","default:ryuichi","ryuichi")
#author("2020-05-11T17:57:10+09:00","default:ryuichi","ryuichi")
* for-inとfor-of [#z6ab752a]
** for in - オブジェクト [#lee54ec1]
** for in - {}オブジェクト [#lee54ec1]
var object = { x: 100, y: 200, z: 300 };
for (var key in object) {
console.log(key, object[key]);
}
object.x = undefined;
console.log(Object.keys(object).length); # 3
delete object.x;
console.log(Object.keys(object).length); # 2
- https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Statements/for...in
** for of - 配列などiterableなオブジェクト [#g2ae420f]
var array = [100, 200, 300];
for (var v of array) {
console.log(v);
}
- for-inの{}はiterableではないのでfor-ofは使えない
- https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Statements/for...of
