How to increment a key in the dictionary?

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?

Please note that JavaScript doesn't have dictionaries, it has objects. — evolutionxbox, Sep 03 '21 at 15:00

score 5 · Accepted Answer · answered Sep 03 '21 at 15:00

5

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)

answered Sep 03 '21 at 15:00

Spectric

score 0 · Answer 2 · answered Sep 03 '21 at 15:07

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.

2 Answers2