var name=prompt("请输入一个三位数:",);
var i=1;
while(i<=3){
if(100<=name&&name<1000&&i==1){document.write("百位:"+parseInt(name/100));
}else if(100<=name&&name<1000&&i==2){
document.write("十位:"+parseInt(name/10)%10);
}else if(100<=name&&name<1000&&i==3){
document.write("个位:"+name%10);
};
i+=1;
}