arr = [{x:1}, {x:3}] arr.reduce((accumulator, current) => accumulator + current.x, 0);
run.addEventListener("click", function () { let sum = people.reduce(function (a, b) { // function(previousValue, currentValue) return { age: a.age + b.age, //select age in object array }; }); console.log(sum); //output sum of ages });
const fruitTally = fruit.reduce((currentTally, currentFruit) => { currentTally[currentFruit] = (currentTally[currentFruit] || 0) + 1 return currentTally } , {}) // returns {"apple":3,"banana":3,"cherry":2,"mango":2,"apricot":1,"guava":2}