实验二1源代码import java.util.*;public class inou private final static Scanner scanner=new Scanner(System.in); public static void main (String args) int a; int b; int c; a=scanner.nextInt(); b=scanner.nextInt(); c=a+b; System.out.println(a=+a); System.out.println(b=+b); System.out.print(a+b=); System.out.println(c); 1.21.源代码public class SimpleMenu public static void main(String a) System.out.println(*); System.out.println(* 1.求圆面积 *); System.out.println(* 2.求圆周长 *); System.out.println(* 0.退出 *); System.out.println(*); 2 源代码public class My public static void main(String a) System.out.println(you.info); class you static String info=同学们好！; 3 源代码import java.awt.*;import java.applet.Applet;public class triangle extends Applet public void paint(Graphics g) g.setColor(Color.red);/设置画笔颜色为红色 g.drawLine(80,20,20,100); g.drawLine(20,100,140,100); g.drawLine(140,100,80,20); g.setColor(Color.blue); /设置画笔颜色为兰色 g.drawString(三角形,65,80); 把三角形文字改成绿色源代码import java.awt.*;import java.applet.Applet;public class triangle extends Applet public void paint(Graphics g) g.setColor(Color.red);/设置画笔颜色为红色 g.drawLine(80,20,20,100); g.drawLine(20,100,140,100); g.drawLine(140,100,80,20); g.setColor(Color.green); /设置画笔颜色为绿色 g.drawString(三角形,65,80); 编程练习 源代码import java.applet.*;import java.awt.Graphics;public class Java_1 extends Applet public void paint(Graphics g) g.drawString(欢迎你来参加 Java 语言考试！,25,25); 正方形源代码import java.applet.Applet;import java.awt.Color;import java.awt.Graphics;public class drawPractice extends Applet public void paint(Graphics g) g.setColor(Color.blue); /设置颜色为蓝色 g.drawRect(10,80,70,60);/画一个正方形 g.setColor(Color.black); g.drawOval(10,80,70,60);/画一个正方形内切圆 g.setColor(Color.red); g.fillOval(100,30,90,90); g.setColor(Color.blue); g.fillOval(120,50,50,50); g.setColor(Color.black); g.drawString(圆心,135,80); 实验三2.1源代码public class test1 public static void main(String args) int a=20; boolean b=true; double c=3014159; char d=a; System.out.println(a+,+b+,+c+,+d); 2.1.1源代码public class test1 public static void main(String args) int a=12345678; boolean b=true; double c=3014159; char d=100;/字符 System.out.println(a+,+b+,+c+,+d); 2.1.2源代码public class test1 public static void main(String args) int a=(int)Math.random(); boolean b=true; double c=3014159; char d=100;/字符 System.out.println(a+,+b+,+c+,+d); 2.1.3源代码public class test1 public static void main(String args) int a=(int)(Math.random()*100); boolean b=true; double c=3014159; char d=100;/字符 System.out.println(a+,+b+,+c+,+d); 2.1.4源代码public class test1 public static void main(String args) int a=(int)(Math.random()*25); boolean b=true; double c=3.14159; char d=a; System.out.println(a+,+b+,+c+,+d); 3.1源代码public class test2 public static void main(String args) int a=20; int b=a+; System.out.println(a+,+b+); 3.1.1源代码public class test2 public static void main(String args) int a=20; int b=+a; System.out.println(a+,+b); 、3.2源代码public class test2 public static void main(String args) int a=20; int b=3; System.out.println(a%b); 3.2.1源代码public class test2 public static void main(String args) int a=20; double b=3.7; System.out.println(a%b); 2.2.2源代码public class test2 public static void main(String args) int a=20; double b=3.2; System.out.printf(%.2f,b); 2.2.3源代码public class test public static void main(String args) int m=0; System.out.println(m+=+m+); System.out.println(+m=+(+m); boolean x; x=(53)&(4=6); System.out.println(x=+x); m=m%2; System.out.println(result=+m+1); int y = m*m+2*m-1; System.out.println(m=+m+,y=+y);