计算平均值时如何从数组中排除零值？

Question

我试图从数组中排除“ 0”值，以获得更好的平均结果。我的数组是：[0，0，0，0，80，90，100，0]function clacGPA(gradeData) {  var sum, avg = 0;  if (gradeData.length) {    sum = gradeData.reduce(function (a, b) {      return a + b;    });    avg = sum / gradeData.length;  }  document.getElementById('gpa').innerText = avg.toFixed(2);}My expected result should be:avg = 80+90+100 / 3

Answer 1

只需先过滤掉0个值：

clacGPA([0, 0, 0, 0, 80, 90, 100, 0]);

function clacGPA(gradeData) {

  const filtered = gradeData.filter(item => item !== 0);

  const sum = filtered.reduce((a, b) => a + b);

  const avg = sum / filtered.length;

  console.log(avg);

}

Answer 2

可以将函数reduce与累加器一起使用，该累加器存储计数和总和。

let arr = [0, 0, 0, 0, 80, 90, 100, 0];

let result = arr.reduce((a, c) => {

  if (c !== 0) {

    a.count++;

    a.sum += c;

  }

  

  return a;

}, {count: 0, sum: 0});

if (result.count) console.log(result.sum / result.count);