java循环结构：求和问题

1.计算1-100之间所有整数的和

package cn.xtnotes.u4;

public class T2 {

	public static void main(String[] args) {
		int sum=0;
		int i=0;
		while (i<=100){
			System.out.println(i);
			sum=sum+i;
			i++;
		}
		System.out.println(sum);
	}
}

2.计算1-100之间所有奇数的和

package cn.xtnotes.u4;

public class T2 {

	public static void main(String[] args) {
		int sum=0;
		int i=1;
		while (i<=100){
			System.out.println(i);
			sum=sum+i;
			i=i+2;
		}
		System.out.println(sum);
	}
}

3.计算1-100之间所有偶数的和

package cn.xtnotes.u4;

public class T2 {

	public static void main(String[] args) {
		int sum=0;
		int i=0;
		while (i<=100){
			System.out.println(i);
			sum=sum+i;
			i=i+2;
		}
		System.out.println(sum);
	}
}

4.输入任意10个数求他们的平均值

package cn.xtnotes.u4;

import java.util.Scanner;

public class T2 {

	public static void main(String[] args) {
		Scanner input=new Scanner(System.in);
		double sum=0;
		int i=1;
		while(i<=10) {
			System.out.println("请输入第"+i+"个数:");
			double shu=input.nextDouble();
			sum=shu+sum;
			i++;
		}
		System.out.println("平均值"+sum/10);
	}
}