2020-10-05 Java练习题

注意：把class后面的类名改成你新建的文件名，然后把下面的代码拷贝运行即可

01: 200个鸡蛋，每打12，几打？余几个？

public class case01 {

	public static void main(String[] args) {
		System.out.println("200个鸡蛋是" + 200/12 + "打");
		System.out.println("剩余" + 200%12 + "个");
	}

}

运行结果：

02：150/0.02/10

public class case02 {
	
	private static double money(double x, double d, int z) {
		for (int i = 1; i <= z; i++) {
			x = x*(1.0+d);
		}
		return x;
	}

	public static void main(String[] args) {
		double cash = 1500000.0;
		double lilv = 0.02;
		int year = 10;
		
		double result = money(cash, lilv, year);
		System.out.println("年利率" + lilv + ",\n" + cash + "元,\n" + "存" + year + "年,\n最后" + result + "元钱。");
	}

}

运行结果：

03： 圆面积

public class case03 {
	
	// 定义PI常量
	final static double PI = 3.1415;
	
	// 面积计算方法
	public static double area(float r) {
		double result = PI*r*r;
		return result;
	}

	public static void main(String[] args) {
		System.out.printf("半径为10的圆面积是：%.2f\n", area(10));
		System.out.printf("半径为20的圆面积是：%.2f\n", area(20));
		System.out.printf("半径为50的圆面积是：%.2f\n", area(50));
	}

}

运行结果：

04：奇数

import java.util.Scanner;

public class case04 {
	
	private static void show() {
		Scanner sc = new Scanner(System.in);
		for (int i = 1; i < 150; i++) {
			System.out.print("Please input a:");
			int a = sc.nextInt();
			System.out.print("Please input b:");
			int b = sc.nextInt();
			
			int mininum = Math.min(a, b);
			int maxinum = Math.max(a, b);
			
			for (int j = mininum; j <= maxinum; j++) {
				if (j%2 == 0) {
					continue;
				}
				System.out.print(j + "\t");
			}
			System.out.println();
		}
	}

	public static void main(String[] args) {
		show();
	}

}

运行结果

09: for/while/do-while 写99乘法表

public class case09 {
	
	// for 循环实现99乘法表
	private static void showDo() {
		for (int i = 1; i <= 9; i++) {
			for (int j = 1; j <= i; j++) {
				System.out.print(j + "x" + i + "=" + j*i + "\t");
			}
			System.out.println();
		}
	}
	
	// while 循环实现99乘法表
	private static void showWhile() {
		int i = 1;
		while(i <= 9) {
			int j = 1;
			while(j <= i) {
				System.out.print(j + "x" + i + "=" + j*i + "\t");
				j++;
			}
			System.out.println();
			i++;
		}
	}
	
	// do/while 循环实现99乘法表
	private static void showDoWhile() {
		int i = 1;
		do {
			int j = 1;
			do {
				System.out.print(j + "x" + i + "=" + j*i + "\t");
				j++;
			} while(j <= i);
			System.out.println();
			i++;
		}while(i <= 9);
	}

	public static void main(String[] args) {
		System.out.println("\nfor循环写的：");
		showDo();
		System.out.println("\nwhile循环写的：");
		showWhile();
		System.out.println("\ndo/while循环写的：");
		showDoWhile();
		
		
	}

}

运行结果：