JSFiddle - React, Tailwind, and code Playground

by Igor Cuckovic

JavaScript

var input = [1,2,3,4,5,5,4]

function pairsFunction(socks) {

	let pairsObj = {}
  let pairs = 0
	

	socks.forEach(d => {
		if (!pairsObj[d]) {
    	pairsObj[d] = 1
    } else if (pairsObj[d]) {
    	pairs += 1
      pairsObj[d] = 0
    }
    
    
  })
  
  return pairs
}

console.log(pairsFunction(input))