ts add a key value pair to a typed object code example

Example 1: key value pairs typescript

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

Example 2: typescript key value array

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

let indexedArray: {[key: string]: number} = {
    foo: 123,
    bar: 456
}

indexedArray['foo'] = 12;
indexedArray.foo= 45;