Question

我是JavaScript的新手，我将这个色彩猜谜游戏作为一项任务。我的脚本如下。我尝试了许多不同的方法，但我无法让它发挥作用。

总之，我有两个问题。

如何检查用户输入的值是否存在于数组中？
如果用户单击“确定”没有值，我该如何确保排除空值？请在此处输入代码

脚本在下面。如果您运行该程序，它将显示用户猜测的答案（仅用于测试）。如果用户猜测正确，则页面颜色将为该颜色。任何帮助将不胜感激。

<DOCTYPE! HTML>
<HTML>
<HEAD>
<TITLE>Color Guessing Game</TITLE>

   </HEAD>

     <body onload="do_game()">

      <script type="text/javascript">

       var target;
       var target_index;
       var guess_input;
       var finished = false;
        var guess_input_text;
       var guesses = 0
        var color= ["Blue","Coral","Cyan","Fuchsia","Gold","Lavender","Lime","Red","Tan"];
         var myBody=document.getElementsByTagName("body")[0];
         var check_color = colors.indexOf(guess_input);

        function do_game(){
        var random_number_integer = colors[Math.floor(Math.random() *  colors.length-1)];
        target = random_number_integer;
         alert(target);

        while (!finished) {

         guess_input_text = prompt("I am thinking of one these colors: \n\n\n" + 
                                colors.toString() + 
                              "\n\n\n What color am I thinkning of?");

    guess_input = guess_input_text;
    guesses += 1;
    finsihed = check_guess(); 
    }
}
  function check_guess() {

       if (guess_input == null){
         alert("Type in a color.");
          return false;
}

if (guess_input > target){
    alert("Your input is alphabetically lower than mine!" +
            "\n\nPlease Try Again.\n\n");
        return false;
}
if (guess_input < target){
    alert("Your input is alphabetically higher than mine!" +
            "\n\nPlease Try Again.\n\n");
    return false;
}

alert("Yes!!!, the correct color was: " + target +
        "\n\n\n The Number of guesses:" + guesses +
        "\n\n\nGood Job\n\n\n");
myBody.style.background=guess_input;
return true;

 }

 </script>
 </body>
 </HTML>

Answer 1

＆＃13;

// check whether the array or string empty
function is_empty(obj){
	if (obj == null || (obj == '' && obj.length == 0)){
		return true;
	}
	else {
		return false;
	}
}


// check whether this elem is included in arr
function is_included(elem, arr){
    if (is_empty(arr) || is_empty(elem) || arr.toString().indexOf(elem) == -1){
        return false;
    }
    else {
        return true;
    }
}

＆＃13;

Answer 2

答案1：使用indexOf：(Docs)

答案2：https://stackoverflow.com/a/20533178/3603806

JavaScript - 数组中的Lookup元素，并处理来自用户提示的空值

2 个答案: