topic Sorting array of values and counting unique values occurrences in Developers Questions

Sorting array of values and counting unique values occurrences

Julia8 — Thu, 09 Jan 2025 11:17:30 GMT

Hi All,

I am struggling with creating a block of code that would sort my array, count unique values, and return them in a text string.

For example: I have this array of fruits:

["Apples", "Bananas", "Berry", "Bananas", "Apples", "Bananas"]

What I would like to get is this output:

Apples x 2, Bananas x 3, Berry x 1

I'm not sure how to get around to this, if it was Feature Set I would use the GroupBy function...

Re: Sorting array of values and counting unique values occurrences

MikeMillerGIS — Thu, 09 Jan 2025 11:39:42 GMT

What language? In python, you can use a Counter

from collections import Counter x = Counter(["Apples", "Bananas", "Berry", "Bananas", "Apples", "Bananas"]) print(x)

Re: Sorting array of values and counting unique values occurrences

TimWestern — Thu, 09 Jan 2025 13:55:19 GMT

In JavaScript/Typescript you might take advantage of the reduce method (granted that 1 liner in python is freaking cool @MikeMillerGIS

Here are two possibilities, one uses an NPM library called lodash the other looks is plain JS/Typescript (no new library needed to install)

JavaScript/Typescript using NPM library lodash (the _ is the import name for lodash in this case)

import _ from "lodash"; function summarizeArray(arr: string[]): string { // Step 1: Count occurrences using _.countBy const counts = _.countBy(arr); // Step 2: Sort keys alphabetically and format the result const summary = _(counts) .toPairs() // Convert object to array of [key, value] pairs .sortBy(0) // Sort by the key (fruit name) .map(([fruit, count]) => `${fruit} x ${count}`) // Format each pair .join(", "); // Join into a single string return summary; } // Example usage const fruits = ["Apples", "Bananas", "Berry", "Bananas", "Apples", "Bananas"]; const result = summarizeArray(fruits); console.log(result); // Output: "Apples x 2, Bananas x 3, Berry x 1"

JavaScript/TypeScript with no additional library needed

Re: Sorting array of values and counting unique values occurrences

DanPatterson — Thu, 09 Jan 2025 14:18:40 GMT

not to leave numpy out

a = ["Apples", "Bananas", "Berry", "Bananas", "Apples", "Bananas"] import numpy as np def uniq(a): """`a` is your array.""" u, cnts = np.unique(a, return_counts=True) st = "" for cnt, v in enumerate(u): st += "{}, {} ".format(v, cnts[cnt]) return st.strip() uniq(a) 'Apples, 2 Bananas, 3 Berry, 1'