console 命令行工具 X clear

console

var num1 = 4;
        var num2= 8;
        if (num1 < 5)
        {
            if (num2 < 5)
            {
                document.write("num1小于5，num2小于5");
            }
            else
            {
                document.write("num1小于5，num2大于5");
            }
        }
        else
        {
            if (num2 < 5)
            {
                document.write("num1大于5，num2小于5");
            }
            else
            {
                document.write("num1大于5，num2大于5");
            }
        }



document.write("<br/>");

//水仙花数
function printDaffodilNum(){
for(var num = 100; num < 1000; num++){
var unitsDigit=num%10;//个位
var tensDigit=parseInt(num/10)%10; /*十位*/
var hundredsDigit=parseInt(num/100);/*百位*/
if (num == (unitsDigit * unitsDigit * unitsDigit + tensDigit * tensDigit * tensDigit + hundredsDigit * hundredsDigit * hundredsDigit)) 
{
document.write("水仙花数有:"+num+"<br/>");
}
}
}
printDaffodilNum();

document.write("<br/>");

function isInteger(num){
    var result = false;
    // 判断num是否是整数
    result = (parseInt(num) == parseFloat(num));

    if (result){
        document.write(num + "is an integer" + "<br/>");
    }
    else {
        document.write(num + "is not an integer" + "<br/>");
    }

    return result;
}

//如果15是整数，输出15是整数
isInteger(15);

//如果15.15 不是整数，输出15，15 不是整数
isInteger(15.15);

document.write("<br/>");

switch (1){
    case 1:
    {
        document.write(1 + "<br/>");
    }
    case 2:
    {
        document.write(2 + "<br/>");
    }
    
    case 3:
    {
        document.write(3 + "<br/>");
    }
  
    default:
    {
        document.write("default <br/>");
    }
}

<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script>
      
    </script>
</head>
<body>
</body>
</html>