javascript - 测验中平均回答正确的问题数

Question

我有一个问 3 个问题的测验应用程序。随着时间的推移，我跟踪正确/错误的答案如下:

var c0 = 143; // Number of users who got 0 questions correct
var c1 = 278; // Number of users who got 1 question  correct
var c2 = 236; // Number of users who got 2 questions correct
var c3 = 185; // Number of users who got 3 questions correct

如何计算用户答对的平均题数？

var averageCorrectQuestions = 2.15; // Example (out of 3)

Answer 1

您可以将计数乘以正确问题的计数，将此值相加并计算所有用户。结果是将总和除以计数。

var c0 = 143,
    c1 = 278,
    c2 = 236,
    c3 = 185,
    [sum, count] = [c0, c1, c2, c3].reduce(([s, c], n, v) => [s + n * v, c + n], [0, 0]);
    
console.log(sum, count);
console.log(sum/count);