javascript中如何生成指定区间的随机数？

<script type="text/javascript">

    // 10 - 20 之间的随机数, 包含10不包含20
    var iN01 = 10;
    var iN02 = 20;
    var aRr2 = [];

    for (var i=0;i<30;i++){
        var iNum02 = Math.floor((iN02-iN01)*Math.random())+iN01;
        aRr2.push(iNum02);
    }

    console.log(aRr2);


    // 10 - 20 之间的随机数, 不包含10包含20
    var iN01 = 10;
    var iN02 = 20;
    var aRr2 = [];

    for (var i=0;i<30;i++){
        var iNum02 = Math.ceil((iN02-iN01)*Math.random())+iN01;
        aRr2.push(iNum02);
    }

    console.log(aRr2);

    // 10 - 20 之间的随机数, 即包含10也包含20
    var iN01 = 10;
    var iN02 = 20;
    var aRr2 = [];

    for (var i=0;i<30;i++){
        var iNum02 = Math.floor((iN02-iN01+1)*Math.random())+iN01;
        aRr2.push(iNum02);
    }

    console.log(aRr2);

</script>