Typescript 初始化为空 object

Question

I'm learning about typescript, and I'm struggling with this code below.

      const profile = state.currentProfile;
      type literalProfile = keyof Partial<Omit<Profile, 'id'>>;

      const values: Record<literalProfile, string | undefined> = {
        name: '',
        avatar: '',
        title: '',
        subtitle: '',
      };

      Object.entries(data).forEach((entry) => {
        const key = entry[0] as literalProfile;
        const value = entry[1];
        if (value && profile[key] !== value) {
          values[key] = value;
        }
      });

      await this.$axios.patch(`/users/profiles/${profile.id}`, values);

The question is, Is there any way to initialize values as an empty object, like this?

const values: Record<literalProfile, string | undefined> = {};

Because if I do something like this typescript highlight me an error

Type '{}' is missing the following properties from type 'Record<"name" |"title" | "subtitle" | "avatar", string | undefined>': name, title, subtitle, avatar

If I try something like this

let values: Record<literalProfile, string | undefined>;

Then typescript says

Variable 'values' is used before being assigned.

In this line

await this.$axios.patch(`/users/profiles/${profile.id}`, values);

So I don't know how to fix that, any ideas?

Answer 1

Currently, you're using Record<listeralProfile, string | undefined> Record<listeralProfile, string | undefined> .

Instead, you should use { [key in literalProfile]?: string } .

There's a subtle difference. Both support undefined as a value, but by using the optional field keyword ? you can omit those fields when initializing your object.

const values: { [key in literalProfile]?: string } = {};