错误设置对象值[JavaScript]

我构建了一个标准偏差计算器，它按照预期使用对象工作。但是，现在我想将每个对象中的newScore属性设置为对象z分数（（分数 - 平均值）/标准偏差）。错误设置对象值[JavaScript]

但是，看起来每个对象都获得了相同的z分值，我不知道为什么。

我在做什么错？

HTML：

<input type="text" id="name" placeholder="Name"> 
<input type="text" id="score" placeholder="Score"> 
<br> 
<br> 
<button id="push">Push to Array</button> 
<button id="show">Show</button> 
<button id="doMath">Do Math</button> 
<ul id="list"></ul> 
<p id="sum"></p> 
<p id="mean"></p> 
<p id="variance"></p> 
<p id="std"></p>

CSS：

input:hover { 
    border: 1px solid black; 
}

的JavaScript：

var myArray = []; 
var sumOfScores; 
var mean; 
var variance; 
var secondArray = []; 
var thirdArray = []; 
var squaredSum; 
var std; 
$(document).ready(function() { 
    $('#push').on('click', function() { 
     var name = $('#name').val(); 
     var score = parseInt($('#score').val()); 
     myArray.push((student = { 
      name: name, 
      score: score, 
      newScore: null 
     })); 
     console.log(student); 
     $('#name').val(""); 
     $('#score').val(""); 
    }); 
    $('#show').on('click', function() { 
     $('#list').html(""); 
     for (i = 0; i < myArray.length; i++) { 
      $('#list').append("<li>" + myArray[i].name + " received a score of " + myArray[i].score + "</li>"); 
     }; 
    }); 
    $('#doMath').on('click', function() { 
     sumOfScores = 0; 
     for (i = 0; i < myArray.length; i++) { 
      sumOfScores += myArray[i].score; 
     }; 
     $('#sum').html("The sum is: " + sumOfScores); 
     mean = (sumOfScores/myArray.length); 
     $('#mean').html("The mean score is: " + mean); 
     variance = 0; 
     for (i = 0; i < myArray.length; i++) { 
      console.log(myArray[i].score); 
      secondArray.push(myArray[i].score - mean); 
     }; 
     console.log(mean); 
     console.log("The second array is: " + secondArray); 
     for (i = 0; i < secondArray.length; i++) { 
      thirdArray.push(Math.pow(secondArray[i], 2)); 
     }; 
     console.log("The third array is: " + thirdArray); 
     squaredSum = 0; 
     for (i = 0; i < thirdArray.length; i++) { 
      squaredSum += thirdArray[i]; 
     }; 
     console.log("The squared sum is: " + squaredSum); 
     variance = 0; 
     variance = (squaredSum/((thirdArray.length) - 1)); 
     console.log("The variance is: " + variance); 
     $('#variance').html("The variance is: " + variance); 
     std = Math.sqrt(variance); 
     $('#std').html("The standard deviation is: " + std); 
     console.log("The standard deviation is: " + std); 
     //figure out z score 
     for (i = 0; i < myArray.length; i++) { 
      myArray[i].newScore = ((myArray[i].newScore - mean)/std); 
     }; 
     for (i = 0; i < myArray.length; i++) { 
      console.log(myArray[i].newScore); 
     }; 
    }); 
});

来源

2015-11-03 adin

您可能需要'（myArray [i] .score - mean）'而不是'（myArray [i] .newScore - mean）'。你的'newScore'默认设置为'null'，所以'null'减去'mean' ..... – Abhitalks

就是这样，谢谢！ – adin

每Abhitalks 61行应改为：

myArray[i].newScore = ((myArray[i].score - mean)/std);

然而，我有：

myArray[i].newScore = ((myArray[i].newScore - mean)/std);

这是行不通的，因为newScore是不是该计算值，并设置为空，你不能繁殖。

来源

2015-11-03 13:27:15 adin

错误设置对象值[JavaScript]

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