Coding Tutorials Blog

Using mutils to supercharge arrays!

October 17, 2020

What is mutils?

mutils is the third in a series of libraries I created in trying to add some extra function to arrays. Let’s explore the history to put this library in context.

MercedUtils: The first version of this library. I wanted to add more array methods and discovered I could add them to the array prototype. This library adds several methods to the array prototype, at this point I learned from others why this is an anti-pattern… because if everyone just added functions to arrays there would possibly be name collisions. So I created a new library taking a different approach.

BetterTypes: In this iteration I created new classes that would take an array and using the eval function and some other tools I was able to replicate all the array methods, but the user experience was definitly not as smooth. Then I learned I could extend the array class.

This brings us to mutils where by extending the Array and Set objects I am able to add plenty of array methods.

How do you Install

Install in your project using npm

npm install mutils_am

them import into your file

const {Rand, MSet, MArray} = require("mutils_am")

Rand

The Rand object has several Random number methods.

Rand.index(Array) => Return random number 0 - Array.length

Rand.range (Low, High) => Return number between low and high

Rand.num (Number) => Return random number 0 - Number

MArray

Create a new MArray object like so…

const myArray = new MArray(1,2,3,4,5)

On top of all the regular array methods (pop, shift, unshift, push, filter, map, etc.) you have all these additional methods!

MArray.random() => return random element from array

MArray.remove((value, index) => return boolean) => the opposite of filter, remove elements where the callback function returns true, returns a MArray

MArray.undupe() => returns a MArray of the array with duplicates removed

MArray.randElim() => eliminates a random element and returns it

MArray.leaveOne() => Randomly eliminates all but one element from array and returns a MArray of removed elements

MArray.leaveSome(number) => Randomly eliminates all but a defined number of elements from array and returns a MArray of removed elements

MArray.findRemove(value) => finds and removes value from array returning the removed value

MArray.addLength(length, value) => increases array to desired length and fills in additional spots with the value passed. Returns itself.

MArray.lessLengthRight(length) => removes elements from back of the array till is desired length, returns array of removed values. Returns itself.

MArray.lessLengthRight(length) => removes elements from front of the array till is desired length, returns array of removed values. Returns itself.

MArray.someMore((value, index) => return boolean, number) => returns true if the number of iterations that return true are equal or greater to the number argument

MArray.everyLess((value, index) => return boolean, number) => returns true if the number of iterations that return false are equal or less to the number argument

MArray.MapToObject((value, index) => return [key, value]) => like map but returns an object, the callback function must return a two element array [key, value]

MArray.MapToMap((value, index) => return [key, value]) => like map but returns a Map, the callback function must return a two element array [key, value]

MArray.MapToSet((value, index) => return [key, value]) => like map but returns a Set

MArray.MapToUnique((value, index) => return [key, value]) => like map but returns an Array of only unique elements

MArray.squish() => removes the first and last elements of the array and returns them in an Marray

MArray.shuff() => return shuffled version of Marray

MArray.toStrings() => return array with all elements casted as strings

MArray.toNums() => return array with all elements casted as Numbers

MArray.toBools() => return array with all elements casted as Booleans

MArray.iPop() => immutable pop, return new version of Marray with last value popped

MArray.iPush(value) => immutable push, return new version of Marray with value pushed into end of array

MArray.iShift() => immutable shift, return new version of Marray with first value removed

MArray.iUnshift(value) => immutable unshift, return new version of Marray with value added at beginning of array

MArray.iSplice(index, amount) => immutable splice, return new version of Marray with the specified number of elements removed starting with the specified index.

MSet

How you create an MSet

const pset1 = new MSet([1, 2, 3, 4]);

MSet.isSuperset(MSet) => Returns true if the MSet is a superset of the MSet passed as an argument

MSet.union(MSet) => Returns a MSet that is a combination of this MSet and the MSet passed in as an argument.

MSet.intersection(MSet) => returns MSet of elements in common between two MSets

MSet.symmetricDifference(MSet) => returns MSet of elements not shared by both MSets

MSet.difference(MSet) => returns MSet of elements not shared by this array with the passed in array


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