javascript - 推送后未定义的数组

Question

我正在尝试从最高到最小对一组山进行排序，但是在尝试打印时，我得到了

TypeError: mountainArray[i] is undefined

我认为我没有遗漏解决方案的任何步骤，但我得到了未定义。

提前致谢

代码如下:

var position;
var height;

function Mountain(position, height) {
  this.position = position;
  this.height = height;
}

function sortMountain(a, b) {
  return b.height - a.height;
}

var mountainArray = [];

// game loop
while (true) {
  for (var i = 0; i < 8; i++) {
    var mountainH = parseInt(readline()); // represents the height of one mountain, from 9 to 0.

    mountainArray.push(Mountain(i, mountainH));
    mountainArray.sort(sortMountain);


  }
  for (var i = 0; i < 8; i++) {
    print(mountainArray[i].position);
  }
}

Answer 1

您编写类(class)的方式:

function Mountain(position, height) {
  this.position = position;
  this.height = height;
}

推送时需要使用new关键字:

while (true) {
  for (var i = 0; i < 8; i++) {
    var mountainH = parseInt(readline()); // represents the height of one mountain, from 9 to 0.

    mountainArray.push(new Mountain(i, mountainH)); // HERE
    mountainArray.sort(sortMountain);


  }
  for (var i = 0; i < 8; i++) {
    print(mountainArray[i].position);
  }
}

正如评论中所指出的，您应该只排序一次，而不需要在循环中每次都这样做。