SOURCE

// 判断是否整数
var num;
function isintger(num) {
var result = false;
 if (parseInt(num) != parseFloat(num)) {
     result = false;

    }
    else {
    result = true;

    }
 return result;
}
var a = 13.44
if (isintger(a)) {
 document.write(a + "是整数"+"<br>")
}
else {
 document.write(a + "不是整数"+"<br>")

 }

// 水仙花 
function dfd() {
    for (var num = 100; num < 1000; num++) {
        var unitsdigit = num % 10;
        var tensdigit = parseInt(num / 10) % 10;
        var hunrdigit = parseInt(num / 100);
        var result = unitsdigit ** 3 + tensdigit ** 3 + hunrdigit ** 3;
        if (num == result) {
            document.write(num + '<br>');
        }
    }
}
dfd();