Java方法总和任意数量的int
我需要编写一个java方法sumAll() ，它接受任意数量的整数并返回它们的总和。
sumAll(1,2,3) returns 6 sumAll() returns 0 sumAll(20) returns 20
我不知道该怎么做。
你需要：
public int sumAll(int...numbers){ int result = 0; for(int i = 0 ; i < numbers.length; i++) { result += numbers[i]; } return result; }
然后调用该方法并根据需要为其提供尽可能多的int值：
int result = sumAll(1,4,6,3,5,393,4,5);//..... System.out.println(result);
如果您使用Java8，则可以使用IntStream ：
int[] listOfNumbers = {5,4,13,7,7,8,9,10,5,92,11,3,4,2,1}; System.out.println(IntStream.of(listOfNumbers).sum());
结果： 181
只需1行代码即可对数组求和。
public int sumAll(int... nums) { //var-args to let the caller pass an arbitrary number of int int sum = 0; //start with 0 for(int n : nums) { //this won't execute if no argument is passed sum += n; // this will repeat for all the arguments } return sum; //return the sum }
使用var args
public long sum(int... numbers){ if(numbers == null){ return 0L;} long result = 0L; for(int number: numbers){ result += number; } return result; }
import java.util.Scanner; public class SumAll { public static void sumAll(int arr[]) {//initialize method return sum int sum = 0; for (int i = 0; i < arr.length; i++) { sum += arr[i]; } System.out.println("Sum is : " + sum); } public static void main(String[] args) { int num; Scanner input = new Scanner(System.in);//create scanner object System.out.print("How many # you want to add : "); num = input.nextInt();//return num from keyboard int[] arr2 = new int[num]; for (int i = 0; i < arr2.length; i++) { System.out.print("Enter Num" + (i + 1) + ": "); arr2[i] = input.nextInt(); } sumAll(arr2); } }
public static void main(String args[]) { System.out.println(SumofAll(12,13,14,15));//Insert your number here. { public static int SumofAll(int...sum)//Call this method in main method. int total=0;//Declare a variable which will hold the total value. for(int x:sum) { total+=sum; } return total;//And return the total variable. } }
你可以这样做，假设你有一个值和数组长度的数组： arrayVal[i] ， arrayLength ：
int sum = 0; for (int i = 0; i < arrayLength; i++) { sum += arrayVal[i]; } System.out.println("the sum is" + sum);
我希望这有帮助。