实验：熟悉java编程环境

（1）java应用程序

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println("**********************");
		System.out.println("Welcome to Java World!");
		System.out.println("**********************");
	}

}

（2）java小应用程序

import java.awt.Graphics;
import java.applet.Applet;
public class minijava extends Applet {
	/**
	 * @param args
	 */
	public void paint(Graphics g) {
		// TODO Auto-generated method stub
		g.drawString("**********************", 10, 20);
		g.drawString("Welcome to Java World!", 10, 40);
		g.drawString("**********************", 10, 60);
	}

}

（3）Fibonacci数列

public class Fibonacci_test {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//裴波那契数列
			System.out.println("Fibonacci的前20位数是:");
			int first = 1;
			int second = 1;
			int next=0;
			for (int i = 1; i < 21; i++) {
				if(i==1){
					System.out.print(first+"\t");//默认加一个换行符
				}
				else if(i==2){
					System.out.print(second+"\t");//默认加一个换行符
				}
				else{
				next = first+second;
				first = second;
				second = next;
				System.out.print(next+"\t");
				if(i%5==0){
					System.out.println("");//默认加一个换行符
				}
			}
		}
	}
}

（4）判断素数

import java.util.Scanner;
public class prime_number {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		while(true){
		Scanner scan = new Scanner(System.in);
		System.out.println("输入正整数：");
		int i = scan.nextInt();
		if(i<0) {
		System.out.println("输入错误！");
		}
		else if(i==1||i==0) {
		System.out.println(i+"既非素数也非合数");
		}
		else {
		boolean isSushu = true; //标记
		for(int j=2;j<i;j++) {
		if(i%j==0) {
		isSushu = false;
		break;
		}}
		if(isSushu==true) {
		System.out.println(i+"是素数");
		}else {
		System.out.println(i+"不是素数");
		}
		}
	}
}
}

本文地址：https://blog.csdn.net/qq_43554335/article/details/110481853