直接上代码
const Arr = [1, 3, 4, 1, 3, 2, 9, 8, 5, 3, 2, 0, 12, 10]
Arr.reduce((acc, cur) => {
if (!(cur in acc)) {
acc[cur] = 1
} else {
acc[cur] += 1
}
return acc
}, {})
// {0: 1, 1: 2, 2: 2, 3: 3, 4: 1, 5: 1, 8: 1, 9: 1, 10: 1, 12: 1}