javascript - 将变量与数组元素进行比较 (javascript)

Question

我试图将数组的每个元素与用户输入进行比较，以便在用户的输入与数组的任何元素不匹配时生成一条消息。我用来做的代码如下。

var guess_input;
var finished = false;
var colors = ["Aqua", "BurlyWood", "Cornsilk", "DarkGrey", "DarkRed", "Indigo", "LightGrey"];

while (!finished) {
          guess_input = prompt("I'm thinking of one of these colors:\n\n" + "Aqua, BurlyWood, Cornsilk, DarkGrey, DarkRed, Indigo, LightGrey" + "\n\nWhat is the color I'm thinking of?");
          finished = check_guess();
          }
      }
      function check_guess() {

       if (guess_input !=  colors[0] || guess_input != colors[1] || guess_input != colors[2] || guess_input != colors[3])  {
          alert("Sorry, I don't recognize that color!\n\n" + "Please try again.");
          return false;
        }
}

这段代码的问题是，如果我只从数组中选择一个元素，它工作得很好。但是当我使用“OR”运算符时，它不起作用。有没有更好的方法来做到这一点？我是 java 脚本新手。

谢谢!

Answer 1

您可以使用logical AND运算符 &&，因为您需要检查所有要检查的颜色。

if (guess_input != colors[0] && guess_input != colors[1] && guess_input != colors[2] && guess_input != colors[3])  {
     alert("Sorry, I don't recognize that color!\n\n" + "Please try again.");
    return false;
}

对于工作代码，您还需要为找到的颜色返回 true。

var guess_input;
var finished = false;
var colors = ["Aqua", "BurlyWood", "Cornsilk", "DarkGrey", "DarkRed", "Indigo", "LightGrey"];

while (!finished) {
    guess_input = prompt("I'm thinking of one of these colors:\n\n" + "Aqua, BurlyWood, Cornsilk, DarkGrey, DarkRed, Indigo, LightGrey" + "\n\nWhat is the color I'm thinking of?");
    finished = check_guess();
}

function check_guess() {
    if (guess_input != colors[0] && guess_input != colors[1] && guess_input != colors[2] && guess_input != colors[3]) {
        alert("Sorry, I don't recognize that color!\n\n" + "Please try again.");
        return false;
    }
    return true; // necessary, otherwise the function returns undefined, which is a falsy value
}