javascript - 我如何迭代(对于 obj 中的键)起始中间位置

Question

我有一个对象:

let obj = {
    1: 'one',
    2: 'two',
    3: 'three',
    7: 'seven'
}

是否有机会从 3 位置开始迭代它，如下所示:

for (let key = 3 in obj) {
     console.log(obj[key]) // An output will be 'three' and 'seven'
}

我需要以最快的方式做到这一点，因为一个对象非常大

Answer 1

用一种简单的方法来做。

let obj = {
  1: 'one',
  2: 'two',
  3: 'three',
  7: 'seven'
};

// make sure that your case is in order

// get keys of your object
const keys = Object.keys(obj);

// find index of starting key
const index = keys.indexOf('3');

// make sure index >= 0

// each all keys from starting key to the end by old school way
for (let i = index; i < keys.length; i++) {
  var key = keys[i];
  console.log(obj[key]);
}