Question

在做警报时，第一个元素的索引，即紫色正在显示-1。但是这对于获得正确的结果是意外的。因此我无法得到任何人帮助我的预期结果以便我可以去进一步编码。实际上是javascript的新手，所以我遇到了这样的问题。希望你能尽快回答。

var colors = ["voilet", "indigo", "blue", "green", "yellow", "orange", "red"];
var target;
var target_index;
var guess_input;
var finished = false;

function do_game() {
  var random_number = Math.random() * 7;
  var random_number_integer = Math.floor(random_number);
  var target_index = random_number_integer;
  target = colors[target_index];
  alert(target);
  while (!finished) {

    var guess_input = prompt("I am thinking of a color " +
      "violet,indigo,blue,green,yellow,orange,red" +
      "What is the color?");
    alert(colors.indexOf(guess_input));
    finished = check_guess();
  }
}

function check_guess() {

  if (colors.indexof(guess_input) < 0) {
    alert('not present');
    return false;
  }
  if (guess_input > target) {
    alert('you gave large');
    return false;
  }
  if (guess_input < target) {
    alert('you gave small');
    return false;
  }
  return true;
}

Answer 1

您说guess_input为violet并返回-1

这是正常行为，因为数组中不存在violet

["voilet","indigo","blue","green","yellow","orange","red"];

存在拼写错误：您写了voilet而不是violet

Answer 2

guess_input在var函数内部使用do_game定义，因此它不是全局的。

您需要删除var，以便可以在其他方法中访问它或将其传递给其他方法。

＆＃13;

/* fixed spelling here */
var colors = ["violet", "indigo", "blue", "green", "yellow", "orange", "red"];
var target;
var target_index;
var guess_input;
var finished = false;

function do_game() {
  var random_number = Math.random() * 7;
  var random_number_integer = Math.floor(random_number);
  var target_index = random_number_integer;
  target = colors[target_index];
  alert(target);
  while (!finished) {
    /* removed var here */
    guess_input = prompt("I am thinking of a color " +
      "violet,indigo,blue,green,yellow,orange,red" +
      "What is the color?");
    alert(colors.indexOf(guess_input));
    finished = check_guess();
  }
}

function check_guess() {

  /* fixed typo here */
  if (colors.indexOf(guess_input) < 0) {
    alert('not present');
    return false;
  }
  if (guess_input > target) {
    alert('you gave large');
    return false;
  }
  if (guess_input < target) {
    alert('you gave small');
    return false;
  }
  return true;
}

do_game()

＆＃13;

Answer 3

检查阵列中紫罗兰的拼写。

和

if (colors.indexof(guess_input) < 0) {
    alert('not present');
    return false;
  }

你也有拼写错误。它应该是：

colors.indexOf(guess_input)

indexOf（）显示意外值

3 个答案: