Question

我想知道为什么我的数组不起作用。难道我做错了什么？我一直在尝试很多不同的阵列但没有工作。我只是错过了一些东西吗？

费用系统：编写一个程序，询问用户的差旅费用。它应该询问费用名称，然后是金额。它应该继续收取费用，直到用户将输入留空。

任何100美元及以下的费用都应自动获得批准。任何超过100美元的费用都不应自动批准。

总计批准和未批准的费用。

首先显示已批准的费用。然后显示需要手动批准的费用。

显示已批准的总费用和总“需求批准”费用。

提前致谢！

//Variables
var expenseName;
var expensePrice;
var loopAgain = true;
var approvedExpenses = new Array();
var approvedExpensePrice = new Array();
var unApprovedExpenses = new Array();
var unApprovedExpensePrice = new Array();
var approvedExpenseTotal = 0;
var unApprovedExpenseTotal = 0;


while(loopAgain) {
  expenseName = prompt("What is the expense? - Type 'done' to end.");
  expensePrice = prompt("What is the price?");
  expensePrice = Number(expensePrice);
  if (expenseName === "done"){
    loopAgain = false;
  }


  for(var count = 0; count < approvedExpenses.length; count++){
    if (expensePrice < 100) {
      approvedExpenseTotal = approvedExpenseTotal + expensePrice;
      approvedExpenses[count] = expenseName;
      approvedExpensePrice[count] = expensePrice;
      }else {
        unApprovedExpenseTotal = unApprovedExpenseTotal + expensePrice;
        unApprovedExpenses[count] = expenseName;
        unApprovedExpensePrice[count] = expensePrice;
      }
  }
}

document.write("APPROVED EXPENSES:<br>");

for(var count = 0; count < approvedExpenses.length; count++){
      document.write(approvedExpenses[count] + ": ");
      document.write(approvedExpenses[count] + "\n");
    }

document.write("EXPENSES NEEDING MANUAL APPROVAL:<br>");

for(var count = 0; count < unApprovedExpenses.length; count++){
      document.write(unApprovedExpenses[count] + ": ");
      document.write(unApprovedExpenses[count] + "\n");
    }

document.write("TOTALS:<br>");

document.write("Total approved expenses: $" + approvedExpenseTotal + "<br>");
document.write("Total expenses waiting approval: $" + unApprovedExpenseTotal + "<br>");

Answer 1

你的程序逻辑有点奇怪。 = b关于为什么没有显示任何内容的具体问题是您的数组是空的。

它们是空的，因为你的for循环没有运行。

你的for循环没有运行，因为for循环中的条件基于“approvedExpenses.length”，它总是为零。

尝试从上到下阅读代码（执行流程）并描绘变量的所有值。它应该揭示approvedExpenses.length为零的原因。

（也在你的for循环中，你设置值的方式可能会最终覆盖现有值，因为计数器总是从0开始，可能存在现有数据）

尝试让数组工作

1 个答案: