TO-KEYED-ARRAY.md

toKeyedArray Function in ts-array

The toKeyedArray function in the ts-array library converts a standard JavaScript object (record) into a proxy object that allows array-like operations. This function is particularly useful when you need to perform operations traditionally reserved for arrays (like map, reduce, forEach, filter) on object properties.

Description

The toKeyedArray function takes an object as input and returns a proxy object. This proxy object mimics the behavior of an array, providing additional methods for object manipulation. It's designed to work with objects where the values are of a consistent type.

Parameters

obj: The object to be converted into a proxy with array-like methods. It should be a record where keys are strings and values are of any consistent type. Returns A proxy object that enables array-like operations on the provided object. This includes methods like map, reduce, forEach, filter, slice, find, findKey, includes, keyOf, and lastKeyOf.

Examples

Using Map on an Object

import { toKeyedArray } from 'ts-array'

const obj = { a: 1, b: 2 }
const keyedArray = toKeyedArray(obj)
const result = keyedArray.map((value, key) => value * 2)

console.log(result)
// Output:
// [2, 4]

Using Filter on an Object

import { toKeyedArray } from 'ts-array'

const obj = { a: 1, b: 2, c: 3 }
const keyedArray = toKeyedArray(obj)
const filtered = keyedArray.filter(value => value > 1)

console.log(filtered)
// Output:
// { b: 2, c: 3 }

Using Reduce on an Object

import { toKeyedArray } from 'ts-array'

const obj = { a: 1, b: 2, c: 3 }
const keyedArray = toKeyedArray(obj)
const sum = keyedArray.reduce((acc, value) => acc + value, 0)

console.log(sum)
// Output:
// 6

Using ForEach on an Object

import { toKeyedArray } from 'ts-array'

const obj = { a: 'first', b: 'second', c: 'third' }
const keyedArray = toKeyedArray(obj)
keyedArray.forEach((value, key) => console.log(key, value))
// Output:
// a first
// b second
// c third

Using Slice on an Object

import { toKeyedArray } from 'ts-array'

const obj = { a: 1, b: 2, c: 3, d: 4 }
const keyedArray = toKeyedArray(obj)
const sliced = keyedArray.slice(1, 3)

console.log(sliced)
// Output:
// [2, 3]

Finding an Element

import { toKeyedArray } from 'ts-array'

const obj = { a: 10, b: 20, c: 30 }
const keyedArray = toKeyedArray(obj)
const found = keyedArray.find(value => value === 20)

console.log(found)
// Output:
// 20

Finding a Key

import { toKeyedArray } from 'ts-array'

const obj = { a: 'apple', b: 'banana', c: 'cherry' }
const keyedArray = toKeyedArray(obj)
const foundKey = keyedArray.findKey(value => value === 'banana')

console.log(foundKey)
// Output:
// b

Checking if a Value is Included

import { toKeyedArray } from 'ts-array'

const obj = { a: 'red', b: 'green', c: 'blue' }
const keyedArray = toKeyedArray(obj)
const hasGreen = keyedArray.includes('green')

console.log(hasGreen)
// Output:
// true

Finding a Key of a Specific Value

import { toKeyedArray } from 'ts-array'

const obj = { a: 'cat', b: 'dog', c: 'bird' }
const keyedArray = toKeyedArray(obj)
const keyOfDog = keyedArray.keyOf('dog')

console.log(keyOfDog)
// Output:
// b

Finding the Last Key of a Specific Value

import { toKeyedArray } from 'ts-array'

const obj = { a: 'circle', b: 'square', c: 'circle' }
const keyedArray = toKeyedArray(obj)
const lastKeyOfCircle = keyedArray.lastKeyOf('circle')

console.log(lastKeyOfCircle)
// Output:
// c