Question

How to count the occurrences of the values in array with Node.js

Answer 1

const arr = [6, 7, 2, 8, 2, 5, 5, 8, 7, 8, 3, 2, 8, 8, 2, 8]

const map = arr.reduce((acc, el) => acc.set(el, (acc.get(el) || 0) + 1), new Map());

console.log([...map.keys()]);
console.log([...map.values()]);
 
 
 
 
/*
run:
 
[ 6, 7, 2, 8, 5, 3 ]
[ 1, 2, 4, 6, 2, 1 ]
 
*/

 

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Answer 2

const arr = [6, 7, 2, 8, 2, 5, 5, 8, 7, 8, 3, 2, 8, 8, 2, 8]

const map = arr.reduce((acc, el) => acc.set(el, (acc.get(el) || 0) + 1), new Map());

console.log([...map.entries()]);
 
 
 
/*
run:
 
[ [ 6, 1 ], [ 7, 2 ], [ 2, 4 ], [ 8, 6 ], [ 5, 2 ], [ 3, 1 ] ]
 
*/

 

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