Pair

"Pair" is a simple pairing class. This module is easy to use, light, small and has no dependencies.

The module is written in TypeScript and compiled into commonJS.

This is not any high-tech code. It is not dependent on 666666 modules and does not offer unseen JavaScript magic. Download this, save a minute of your time and use it to make some coffee. We #keepItSimple.

Download

You can download the module on GitHub/value-pair or using npm/value-pair service.

npm install value-pair --save

Pair - What is that? (skip if you know)

Pair is super simple and intuitive class for merging two values. It may be objects, strings, object and string, array and number, booleans, really whatever you need.

These types of classes are most often used to store a key and a value. If you need to save more than two values and keep them together, it is highly recommended to create new and custom class.

//HOW TO STORE KEY AND ITS VALUE?
//Let's show an example. We want to store numbers and their "string form".

//-----One possible solution without objects - two arrays-----
var keys = [
	"zero",
	"one",
	"two",
	"three"
];
var values = [
	0,
	1,
	2,
	3
];

//There are several problems with this one. For example, sorting, moving and the worst one: difficult modification and adding new features.

//-----Well, that is just stupid, let's don't do that. Try objects:-----

var keysAndValue = [
	{ key: "zero", value: 0 },
	{ key: "one", value: 1 },
	{ key: "two", value: 2 },
	{ key: "three", value: 3 }
];

//-----Yes, that is better, but what if we didn't have to write those annoying "key" and "value" words? What if we add some elegance?-----

var pairs = [
	new Pair("zero", 0),
	new Pair("one", 1),
	new Pair("two", 2),
	new Pair("three", 3);
];

//Yes, I love it. Do you?

//-----It goes without saying, but if you need to save more than two values, DON'T DO THIS-----
var numbers = new Pair("one", new Pair("two", new Pair("three", "four"))); //DON'T
//PLEASE DON'T, really, I am serious :D

The style is up to you. I like the Pair class and that is why I share it with you. The "unnamed objects style" is also not bad, but under no circumstances, do not use two arrays for handling keys and values. Trust me, I know.

Summary: The Pair class is useful and elegant for pairing keys and values or just some two values, but there are more solutions and alternatives. It is up to you to choose one.

Usage

Import and create new Pair

You can import the module using import keyword or require function. In TypeScript, the Pair class is a generic class ("<>" thingies).

import { Pair } from "value-pair";

//Instantiate new and empty Pair
var pair = new Pair(); // Both values are now null

//Instantiate new pair with values
var pair = new Pair("key", 1);

//For TypeScript programmers: Pair is a generic class, so declaration in TypeScript would look like:
let pair = new Pair<string, number>("key", 1); //<string, number> or whatever data type you want to store and work with

var P = require("value-pair");

//Instantiate new Pair
var pair = new P.Pair("key", 1);

Pair

Working with the Pair is easy. Here are all the implemented methods:

//Instantiate new Pair
var pair = new Pair("key", 1); //If no constructor parameters provided, the values are null

//Get first (key) value
var key = pair.first;

//Get second ("value") value
var value = pair.second;

//If you store string, boolean or number, you can print those values (debug)
pair.Print();

I used "first" and "second" instead of "key" and "value" for general purpose. You can use the Pair class anywhere, not just as a storage for keys and values. I also developed this based on C++ STD.

Sorry for my English, I hope it's readable.