Finding out how many times an array element appears in javascript and return from big to small

Question

As a reference to this question the idea is same

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

But

instead of deleting the duplicates I want them to show app

numArr=["hi", "apple", "window", "hi", "go", "window", "phone", "go", "hi", "down", "hi"];

At first I just wanna to know what function is that do find repeated items I think for python which I put hand on it is not that hard but seem here hard is javascript in addition I said I will try to find on google which do what I want but every code is harder to another code so before asking here I get a popular question which I provide the link above I just checked around but every code is harder then another so at that moment I decided to ask you here

and the result it show the same like this below

"hi","book","goal" appeared 4 times

"window","door","pencil","speaker" appeared 2 times

or I say every (number like four times appeared) make a new array look the easy if by number appeared or by order from a-z

notice that: - When I give to anyone he can pass his words and see his final result -I want the code to show in order from a-z and from big to small - the code or the function must accept even the words in array are million and above -even there is another words show same number of times display them.

Answer 1

I'll give you the logic that you need, and invite you to take a crack at figuring out how to write the code. As several others have mentioned, we're not going to do it for you, but I'll be glad to see if I can teach you how to do it yourself.

First, create a two-dimensional array (i'll call it myResult). The first dimension will contain each distinct value from your numArr array. The second dimension will contain the total times that the value occurs in your array.

Now, use a for loop to iterate your array (means run through it from the beginning to the end). Each time you go through the loop, do these:

1. Look in myResult for the value of the current array element (use findIndex(), so you can get the index of where it is).
2. If you don't find it, add it to the array (use push()). Then, change the value of the second dimension to 1.
3. If you do find it, just add 1 to the value of the second dimension (the first dimension's index will be the index you found using findIndex, while the second dimension's index will always be zero -- you're never going to have more than one total value for each of your array's values).

Once all that's done, you can iterate your myResult array and print your results (use console.log() to start; once you have it working the way you want you can work on getting it to print where you want it).

I suggest you read up and familiarize yourself with the methods I've recommended, and see if you can come up with your solution. If you have any questions, please ask in the comments. w3schools.com is an excellent place to start.