有只小跳蛙
public class ThreeNumber {public static void main(String agrs[]) {int t=0;for (int i=100; i<=1000;i++) {if (i%3 == 0) {System.out.printf("%4d",i);t++;if(t%6==0)System.out.println(""); //每行打印6个数}}}}2.public class CiFang {public static void main(String agrs[]) {System.out.println(find2(40));}static double find2 (int n) {return Math.pow(2, n);}}3.public class ShowCar {public static void main(String[] args) {Car bentian = new Car("本田","黑色",1500,5);System.out.println("品牌:"+bentian.name);System.out.println("颜色:"+bentian.color);System.out.println("自重:"+bentian.weight+"公斤");System.out.println("搭乘人数:"+bentian.passenger);}}class Car {String name;String color;double weight;int passenger;public Car (String name,String color,double weight,int passenger) {this.name = name;this.color = color;this.weight = weight;this.passenger = passenger;}}4.public class Array {public static void main(String[] args) {int []number = {5,6,1,7,3};int min = number[0],max =number[0],sum = number[0];for(int i=1;i<number.length;i++) {sum = sum +number[i];if (number[i]<min)min = number[i];if(number[i]>max)max = number[i];}System.out.println("数组元素和:"+sum);System.out.println("数组最小元素:"+min);System.out.println("数组最大元素:"+max);}}5.import java.io.*;public class TestString {private String input;String[] strs = new String[10]; //根据输入生成的字符串数组private static BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));private static PrintWriter stdOut = new PrintWriter(System.out,true);public void inputString() throws IOException{stdOut.println("请输入10个以内的字符串,输入exit结束输入:");int i = 0;while((input = stdIn.readLine())!=null){String[] temp = new String[i+1];if(input.equals("exit"))break;strs[i] = input;i++;}for(int k = 0;k<i;k++)System.out.println(strs[k]);}public static void main(String[] args){try {new Homework().inputString();} catch (IOException e) {e.printStackTrace();}}}最后一个程序可能不是很完善,最多只能输入十个字符串!