输入分数并计算平均值

Question

我是JavaScript的新手，即使我知道它应该很简单，所以请帮忙！ 我知道有一些类似的主题，但我需要使用这个模板

这是我的任务：

允许用户输入七个不同的分数 计算所有这些分数的平均值 在屏幕上显示平均值

到目前为止我所拥有的：

// init vars, get input from user
var scores = [1,2,3,4,5,6,7];

score[0] = (prompt("Type in a Score 1 of 7") )
score[1] = (prompt("Type in a Score 2 of 7") )
score[2] = (prompt("Type in a Score 3 of 7") )
score[3] = (prompt("Type in a Score 4 of 7") )
score[4] = (prompt("Type in a Score 5 of 7") )
score[5] = (prompt("Type in a Score 6 of 7") )
score[6] = (prompt("Type in a Score 7 of 7") )

function calculate() {
    for (var i = 0; i < scores.length; i++) {
        total += score[i];
    }
    average = (total / scores.length).toFixed(2);
}

function getscores() {
    while (scores.length < 7) {
        scores.push(parseInt(prompt("Please input a score")));
    }
}

getScores();
calculate();
showScores();

function showScores() {
    document.write("The average of those scores is: " + average);
}

Answer 1

您应该使用total定义var并分配到0：

 function calculate() {
   var total = 0;
   for (var i = 0; i < scores.length; i++) {
     total += scores[i];
   }
    average = (total / scores.length).toFixed(2);
 }

另外，您应该像使用范围一样设置average全局：

var average;

Answer 2

这应该有效：

var score = [];

function getScores() {
    while (score.length < 7) {
        score.push(parseInt(prompt("Please input a score")));
    }
}

function calculate() {
    var total = 0;
    for (var i = 0; i < score.length; i++) {
        total += score[i];
    }
    average = (total / score.length).toFixed(2);
}

function showScores() {
    alert("The average of those scores is: " + average);
}

getScores();
calculate();
showScores();

<强> Working JSFiddle Example