Typescript-初始化嵌套的哈希对象

Question

I'm kinda new on typescript, and I really don't know how to approach this: I wanna initialize a hash object with 0 values... something like that:

let values;

for(let year of this.years_collection){
    for(let month of this.months_collection){
        this.values[year][month] = 0;
    }
}

But this syntax is clearly invalid. How could I do that, in a way that I would get a nested hash with my month and years, all then with 0 values seted? Thanks in advance!

Answer 1

Something like this:

let values = {} as {
    [key: string]: { [key: string]: number };
};

for (let year of this.years_collection) {
    for (let month of this.months_collection) {
        if (!this.values[year]) {
            this.values[year] = {}
        }

        this.values[year][month] = 0;
    }
}