Array.push导致程序出错 [英] Array.push causes program to have errors

问题描述

我按照上一个问题的建议让我的提示向数组添加值，但是这导致我的程序在没有True值时抛出它们。

I followed the advice from a previous question to get my promps to add values to an array, but it has caused my program to throw up True values when they are not.

HIGHEST_GRADE = 7;
LOWEST_GRADE = 0;

var course = new Array();
var grade = new Array();

while(confirm("Would you like to add a course?")){
    course.push( prompt("Enter the course code. Example - ABC1234") );
};

var upperTest = course.slice(0,3);
var integerTest = course.slice(4,7);

if (course.length !== 7) {
    alert ('Invalid Course Code');
}

if (upperTest !== upperTest.toUpperCase()) {
     alert ('Invalid Course Code');
}

if (isNaN(integerTest)) {
    alert('Invalid Course Code'); 
}

if (isNaN(grade)) {
    alert('Invalid Grade');
}

if (LOWEST_GRADE > grade || HIGHEST_GRADE < grade) {
    alert('Invalid Grade');
}       

我将其设置为确保输入的文本符合条件，但是由于

I have it set to make sure the entered text matches the conditions, but since the .push was added the whole thing stuffs up.

我收到无效的课程代码错误，有些东西正在起作用。

I get an Invalid Course Code error, something is playing up with that.

推荐答案

Array 用于存储多个课程，这很好。但是，由于它是一个数组，因此需要使用循环访问它的每个位置以验证每个个人课程：

The Array is used to store multiple courses, which is fine. But, since it's an array, you need to access each position of it to validate each individual course, using a loop:

var courses = new Array();  // use the name courses instead, to indicate that it's a collection

for (var i = 0; i < courses.length; i++) {
  var course = courses[i];

  var upperTest = course.slice(0,3);
  var integerTest = course.slice(4,7);

  if (course.length !== 7) {
    alert ('Invalid Course Code');
  }

  if (upperTest !== upperTest.toUpperCase()) {
    alert ('Invalid Course Code');
  }

  if (isNaN(integerTest)) {
    alert('Invalid Course Code'); 
  }
}

这将验证每个课程位于 Array 中。否则，当您测试 courses.length 时，您将验证数组中元素的数量，而不是每个课程的字符数

This will validate every course that is in the Array. Otherwise, when you test courses.length, you'll be validating the number of elements in the array, not the number of characters of each course.

对于成绩数组也需要执行相同的操作。

The same needs to be done for the grades array.

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