JavaScript Problem: Comparing Two Arrays without Loops

We are going to tackle another JavaScript problem in this tutorial. The specific problem is how one can compare two arrays without using any loops.

Would you like to help keep this channel going?

Tutorials referred to in this video:

For more resources on JavaScript:

#javascript #AllThingsJavaScriptLLC

[amatiasq]

"Comparing Two Arrays without Loops", then proceeds to nest a `.reduce()` inside a `.map()`...

[AllThingsJavaScript]

So grateful for all of you tuning in each week and for your feedback and encouragement. Glad you are all trying to improve your JavaScript skills! #GiveThanks

[tirmey]

Mapping over an array is kind of intrinsically lopping over it, no? nice solution, anyway!

[zbjptid]

Thanks Steve for going to such great lengths to answer the query... you are a legend sir :)

[magnusfohlstrom]

Without reduce...
function compareArray( searchArray, targetArray ) {
return searchArray.map(curr => ({[curr]: targetArray.filter(check => curr === check).length}));
}

[MuhammadAdnan.]

Have to practice this two time arrays comparing.... 😃

[magnusfohlstrom]

returns from one line...
function compareArray( searchArray, targetArray ) {
return searchArray.reduce((obj, curr) => [...obj, {[curr]: targetArray.filter(check => curr === check).length}], []);
}

[lidwinguillermogascagarcia]

I just started learning js, and to acomplish my project, I need to compare two arrays of food recipes, one is the recipe, and the other array is the ingredients the user have, all I need to do is to check if the users ingredients array contains the ingredients from the recipe array, if true, show a picture of the recipe (trying to make an app that will show me what dishes I could cook with my ingredients).

[Charlie_]

i was under the impression that those higher order functions map, filter, reduce etc.. all had built in loops to them.

[ScottL]

Nice tutorial, thanks. IMO, it would be more helpful and relevant if you were to use arrow functions.

[hamidrezaakbarnezhad]

so pretty really. I like that. Please solve problems that contains array of objects and operate on each them... and compare solutions in performance and that what is best solution. Tnks

[TheSwagStatus]

wordList.filter( conditional checking for === with word in wordCheck).length

[chrismiller]

Wouldn't JSON.parse(JSON.stringify) work for this? I use it for comparing an array of objects

[MiroslavPopov]

Hahahah. No loop but map and reduce :)))). Dislike.

[magnusfohlstrom]

.map .filter .reduce internally they use loop technically.
function compareArray( searchArray, targetArray ) {
let objArray = [],
searchArrayLen = searchArray.length,
targetArrayLen = targetArray.length,
tot = 0,
count = (search, controller = 0) => {
tot = targetArray[controller] === search ? tot + 1 : tot;
++controller !== targetArrayLen && count(search, controller);
};

(function fill(controller = 0) {
tot = 0;

objArray[controller] = {[searchArray[controller]]: tot};
++controller !== searchArrayLen && fill(controller);
})();
return objArray;
};