Is key-value pair available in Typescript?

Question

Is key-value pair available in Typescript?

Yes. Called an index signature:

interface Foo {
   [key: string]: number;
}


let foo:Foo = {};
foo['hello'] = 123;
foo = {
  'leet': 1337
};
console.log(foo['leet']); // 1337

Here keys are string and values are number.

More

You can use an es6 Map for proper dictionaries, polyfilled by core-js.

The simplest way would be something like:

var indexedArray: {[key: string]: number}

Usage:

var indexedArray: {[key: string]: number} = {
    foo: 2118,
    bar: 2118
}

indexedArray['foo'] = 2118;
indexedArray.foo= 2118;

let foo = indexedArray['myKey'];
let bar = indexedArray.myKey;

You can also consider using Record, like this:

const someArray: Record<string, string>[] = [
    {'first': 'one'},
    {'second': 'two'}
];

Or write something like this:

const someArray: {key: string, value: string}[] = [
    {key: 'first', value: 'one'},
    {key: 'second', value: 'two'}
];

Is key-value pair available in Typescript?

If you think of a C# KeyValuePair<string, string>: No, but you can easily define one yourself:

interface KeyValuePair {
    key: string;
    value: string;
}

Usage:

let foo: KeyValuePair = { key: "k", value: "val" };

Not for the questioner, but for all others, which are interested: See: How to define Typescript Map of key value pair. where key is a number and value is an array of objects

The solution is therefore:

let yourVar: Map<YourKeyType, YourValueType>;
// now you can use it:
yourVar = new Map<YourKeyType, YourValueType>();
yourVar[YourKeyType] = <YourValueType> yourValue;

Cheers!