如何在JavaScript中的两个指定变量之间生成随机整数,例如x=4和y=8将输出4、5、6、7、8中的任意一个?


当前回答

其他答案没有考虑到0和1这两个完全合理的参数。相反,您应该使用圆形而不是天花板或地板:

function randomNumber(minimum, maximum){
    return Math.round( Math.random() * (maximum - minimum) + minimum);
}

console.log(randomNumber(0,1));  # 0 1 1 0 1 0
console.log(randomNumber(5,6));  # 5 6 6 5 5 6
console.log(randomNumber(3,-1)); # 1 3 1 -1 -1 -1

其他回答

var randomnumber = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;

以下是排字的解决方案

function getRandomInt(min:number, max:number):number {
    return min+Math.round(Math.random() * (max-min));
  }

  for(let i:number=0; i<100; i++){
  console.log(`${i+1} >> ${getRandomInt(1,6)}`)

  }

最低和最高之间的随机整数:

function randomRange(low, high) {
  var range = (high-low);
  var random = Math.floor(Math.random()*range);
  if (random === 0) {
    random += 1;
  }
  return low + random;
}

这不是最优雅的解决方案,而是快速的解决方案。

function getRandomInt(lower, upper)
{
    //to create an even sample distribution
    return Math.floor(lower + (Math.random() * (upper - lower + 1)));

    //to produce an uneven sample distribution
    //return Math.round(lower + (Math.random() * (upper - lower)));

    //to exclude the max value from the possible values
    //return Math.floor(lower + (Math.random() * (upper - lower)));
}

要测试此函数以及此函数的变体,请将以下HTML/JavaScript保存到文件中,然后用浏览器打开。该代码将生成一个图表,显示一百万个函数调用的分布。代码还将记录边缘事例,因此如果函数产生的值大于最大值,或小于最小值,则您将知道大约。

<html>
    <head>
        <script type="text/javascript">
        function getRandomInt(lower, upper)
        {
            //to create an even sample distribution
            return Math.floor(lower + (Math.random() * (upper - lower + 1)));

            //to produce an uneven sample distribution
            //return Math.round(lower + (Math.random() * (upper - lower)));

            //to exclude the max value from the possible values
            //return Math.floor(lower + (Math.random() * (upper - lower)));
        }

        var min = -5;
        var max = 5;

        var array = new Array();

        for(var i = 0; i <= (max - min) + 2; i++) {
          array.push(0);
        }

        for(var i = 0; i < 1000000; i++) {
            var random = getRandomInt(min, max);
            array[random - min + 1]++;
        }

        var maxSample = 0;
        for(var i = 0; i < max - min; i++) {
            maxSample = Math.max(maxSample, array[i]);
        }

        //create a bar graph to show the sample distribution
        var maxHeight = 500;
        for(var i = 0; i <= (max - min) + 2; i++) {
            var sampleHeight = (array[i]/maxSample) * maxHeight;

            document.write('<span style="display:inline-block;color:'+(sampleHeight == 0 ? 'black' : 'white')+';background-color:black;height:'+sampleHeight+'px">&nbsp;[' + (i + min - 1) + ']:&nbsp;'+array[i]+'</span>&nbsp;&nbsp;');
        }
        document.write('<hr/>');
        </script>
    </head>
    <body>

    </body>
</html>

为了获得最佳性能,您只需使用:

var r = (Math.random() * (maximum - minimum + 1) ) << 0