如何增加字典中的键？

Question

I'm new to javascript and I'm trying to increment a key in the dictionary

 var dic = {} for (let i = 0; i < 100; i++) { dic['key']++ } console.log(dic)

I don't get the incremented number, where am I going wrong?

Answer 1

You are trying to increment undefined since there is no key property in dic , thus you get NaN .

Instead, give the key property a default value:

 var dic = {key: 0} for (let i = 0; i < 100; i++) { dic['key']++ } console.log(dic)

Answer 2

var dic = { count1: 0, count2: 10 }

for (var i in dic) {
    if (i === 'count1') {
        dic[i]++;
    }
}
console.log(dic);

Are you trying to do anything like this? here you are iterating through the object, if i equals the key you are looking for, it will increment it.