Question

我想创建一个项目列表，其中随机选择项目，并从不同的组中选择每个项目。我对此非常陌生，但这段代码似乎也是这样。

<html>
<body>
<p>Random items from three different groups:</p>
<script type="text/javascript">
<!--
document.write('<ol>');
  // first group
  var first_group = new Array ();
  first_group[0] = "one";
  first_group[1] = "two";
  first_group[2] = "three";
  var i = Math.floor(3*Math.random())
  document.write('<li>' + first_group[i]);
  // second group
  var second_group = new Array ();
  second_group[0] = "three";
  second_group[1] = "four";
  second_group[2] = "five";
  var i = Math.floor(3*Math.random())
  document.write('<li>' + second_group[i]);
  // third group
  var third_group = new Array ();
  third_group[0] = "five";
  third_group[1] = "six";
  third_group[2] = "seven";
  var i = Math.floor(3*Math.random())
  document.write('<li>' + third_group[i]);
document.write('</ol>');
//-->
</script>
</body>
</html>

是否可以修改代码，以便即使相同的项目出现在多个组中，同一项目也不会在最终列表中出现多次？（例如，如果从第一组中选择“三”，则无法从第二组中选择。）并且是否可以按随机顺序排列最终列表？任何有关其他改进的建议也是受欢迎的。

Answer 1

试试这个：

<html>

<body>
    <p>Random items from three different groups:</p>
    <script type="text/javascript">
        var selectedValues = [];

        function chooseRandom(array) {
            // Select random number until it's a number that wasn't selected yet
            do {
                var random = Math.floor(array.length * Math.random());
                var randomResult = array[random];
            } while (selectedValues.indexOf(randomResult) > -1)

            // Log the selected number so it won't be selected randomly again
            selectedValues.push(randomResult);
            return randomResult;
        }

        document.write('<ol>');
        var first_group = ["one", "two", "three"];
        var second_group = ["three", "four", "five"];
        var third_group = ["five", "six", "seven"];

        document.write('<li>' + chooseRandom(first_group) + '</li>');
        document.write('<li>' + chooseRandom(second_group) + '</li>');
        document.write('<li>' + chooseRandom(third_group) + '</li>');

        // Finalize
        document.write('</ol>');
    </script>
</body>

</html>

Answer 2

使用自定义JavaScript函数是最好的方法。根据您的示例（您可能需要扩展到更复杂的生态系统：

<script type="text/javascript">
<!--
var i=j=k=x=0;

var first_group = ["one", "two", "three"]; 
var second_group = ["three", "four", "five"]; 
var third_group = ["five", "six", "seven"]; 

 i = Math.floor(3*Math.random());
 j = Math.floor(3*Math.random());
 k = Math.floor(3*Math.random());

var okayArray=makeNoDup(first_group,i,second_group,j,third_group,k);

document.write('<ol>');
okayArray.forEach(function(e) {
   document.write('<li>' + e[x] + '</li>');
   x++;
}
document.write('</ol>');


function makeNoDup(first,i,second,j,third,k){
  if(first[i] === second[j]){    
     var newj = Math.floor(3*Math.random());
     j= makeNoDup(first, i, second, newj, third, k);
  }
  if(first[i] === third[K]  || second[j] === third[k]){    
     var newK = Math.floor(3*Math.random());
     k= makeNoDup(first, i, second, j, third, newk);
  }
  var answer = {
    first: i,
    second: j,
    third: k
  };
  return (answer);
}
//-->
</script>

关键是递归函数makeNoDup。

随机选择的项目列表

2 个答案: