function findOdd(A) { let counts = A.reduce((p, n) => (p[n] = ++p[n] || 1, p), {}); return +Object.keys(counts).find(k => counts[k] % 2) || undefined; }
var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]; var evenNumbers = numbers.filter(function(item) { return (item % 2 == 0); }); console.log(evenNumbers);
///sum of odd numbers in an array javascript without loop var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]; var evenNumbers = numbers.filter(function(item) { return (item % 2 == 0); }); console.log(evenNumbers);
var total = numbers.reduce(function(total, current) { return total + current; }, 0); console.log(total);