方法一:
var sum =0;functionf(){for(var i =1; i <=100; i++){
sum += i;}
console.log(sum);}f();
方法二:
functiongetSum(start,end){var sum=0;for(var i=start;i<=end;i++){
sum += i;}
console.log(sum);}getSum(1,100)
2、利用函數求任意兩個數的和(例如:1,2)
方法一:
functiongetSum(num1, num2){var sum =0;
sum = num1 + num2;
console.log(sum);}getSum(1,2);
方法二:
functiongetNum(num1, num2){return num1+num2 ;}
console.log(getNum(1,2));
functiongetMax(arr){var max = arr[0];for(var i =0; i <= arr.length; i++){if(arr[i]> max){
max = arr[i]}}return max;}var re =getMax([5,2,99,101,67,77]);//在實際開發中,常用變量接收返回值
console.log(re);
var arr =[2,4,1,2,4,5,9,5];functionf(arr){for(var i =0; i < arr.length; i++){for(var j = i +1; j < arr.length; j++){if(arr[i]== arr[j]){
arr.splice(j,1);}}}}f(arr);
console.log(arr);
functionisLeapYear(year){// 如果是閏年返回true,否则返回false var flag =false;if(year %4==0&& year %100!=0|| year %400==0){
flag =true;}return flag;}
console.log(isLeapYear(2000));
console.log(isLeapYear(1999));
12、利用函數輸出某年份2月的天數(函數相互調用)
functionbackDay(){var year =prompt('请您输入年份:');if(isLeapYear(year)){alert('當前年份是閏年2月有29天');}else{alert('當前年份是閏年2月有28天');}}backDay();//判斷是否是閏年functionisLeapYear(year){// 如果是閏年返回true,否则返回false var flag =false;if(year %4==0&& year %100!=0|| year %400==0){
flag =true;}return flag;}
console.log(isLeapYear(2000));
console.log(isLeapYear(1999));