SOURCE

switch(1){
    case 1:
    {
        document.write(1+"<br/>");
    }
    case 2:
    {
        document.write(2+"<br/>");
    }
    case 3:
    {
        document.write(3+"<br/>");
    }
    break;
    default:
    {
        document.write("default <br/>");
    }
}
document.write("-------------------------------------------- <br/>");
function isInteger(num){
    var result=false;
if(parseInt(num)==parseFloat(num)){
    result=true;
}else{
    result=false;
}
    return result;
    return result;
}
if (isInteger(15)){
    document.write("15是整数"+"<br/>");
}
if (isInteger(15.15)){
    document.write("15.15是整数"+"<br/>");
}else{
    document.write("15.15不是整数"+"<br/>");
}

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

function printDaffodilNumber(){
    document.write("Print out all daffodil number(水仙花数):"+"<br/>");
    for (var num=100;num<1000;num++){
        var a=num%10;
        var b=parseInt((num/10)%10);
        var c=parseInt(num/100);

        if(num==a*a*a+b*b*b+c*c*c){
            document.write(num+"<br/>");
        }
    }
}
printDaffodilNumber();

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

function isInteger(num){
    var result=false;
    var num=5.20;
    if(parseInt(num)==parseFloat(num)){
        result=true;
    }
    return result;
}
if (isInteger(5.20)){
    document.write("5.20 是一个整数");
}else{
    document.write("5.20 是一个小数");
}