CODEWITHSUNDEEP
typescript
Mary
Mary

Reputation: 1145

In TypeScript, how can I specify the types of the values in my object?

For example, suppose I have:

export function trade(positions: object) {
  ...
}

but instead of just specifying that 'positions' is an object, I want to specify that it is an object with values that must be Strings.

What is the syntax for that?

Edit:

To tighten the example, suppose I just want keys and values to all be Strings. Is there a syntax for that?

Upvotes: 0

Views: 52

Answers (1)

Fenton
Fenton

Reputation: 251262

If you want to share the object is as wide as "has string keys, and string values" you can use an index type:

export function trade(positions: {[key: string]: string;}) {
    // ...
}

If you want to make it more specific, it may be time to create an interface - even if everything is optional - as it will give you more design-time help when creating a positions object.

interface Positions {
    x?: string;
    y?: string;
    z?: string;
    t?: string;
}

This doesn't force any of the items to be present, but you'll get good auto-completion. If the members are required, you can make them non-optional.

Upvotes: 2

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