JAVA语言程序设计（基础篇）原书第10版第1章编程练习题答案

1

public class test1 {
    public static void main(String[] args){
        System.out.println("Welcome to Java");
        System.out.println("Welcome to Computer Science");
        System.out.println("Programming is fun");
    }
}

2

public class test2 {
    public static void main(String[] arg){
        for(int i=0;i<5;i++)
            System.out.println("Welcome to Java");
    }
}

3

public class test3 {
    public static void main(String[] arg) {
           System.out.println("       J           A         V           V         A");
           System.out.println("        J        A   A         V        V        A   A");
           System.out.println("  J     J      A A A A A         V   V         A A A A A ");
           System.out.println("    J  J      A         A          V         A           A");
    }
}

4

public class test4 {

	public static void main(String[] args) {
        System.out.println("a       a^2       a^3");
        System.out.println("1        1         1");
        System.out.println("2        4         8");
        System.out.println("3        9         27");
        System.out.println("4        16        64");
	}

}

5

public class test5 {

	public static void main(String[] args) {
         double a;
         a=(9.5*4.5-2.5*3)/(45.5-3.5);
         System.out.println(a);
	}

}

6

public class test6 {

	public static void main(String[] args) {
         int sum=0;
         for(int i=1;i<=9;i++)
        	 sum+=i;
         System.out.println(sum);
	}

}

7

public class test7 {

	public static void main(String[] args) {
         double a,b;
         a=4*(1.0-1.0/3+1.0/5-1.0/7+1.0/9-1.0/11);
         b=4*(1.0-1.0/3+1.0/5-1.0/7+1.0/9-1.0/11+1.0/13);
         System.out.println(a);
         System.out.println(b);
	}

}

8

public class test8 {

	public static void main(String[] args) {
        double Length,Area;
        Length=Math.PI*2*5.5;
        Area=Math.PI*5.5*5.5;
        System.out.println("半径为5。5的周长和面积分别为"+Length+","+Area);
	}

}

9

public class test9 {

	public static void main(String[] args) {
         double Length,Area;
         Length=2*4.5*7.9;
         Area=4.5*7.9;
         System.out.println("宽度为4.5，高度为7.9的矩形的面积和周长分别为"+Area+","+Length);
	}

}

10

public class test10 {

	public static void main(String[] args) {
          double time=45.5/60;
         double s=14.0/1.6;
         double v=s/time;
         System.out.println(v);
	}

}

11

public class test11 {

	public static void main(String[] args) {
       double s1,s2,s3,s4,s5;
       s1=312032486+365*24*60*60/7+365*24*60*60/45-365*24*60*60/13;
       s2=s1+365*24*60*60/7+365*24*60*60/45-365*24*60*60/13;
       s3=s2+365*24*60*60/7+365*24*60*60/45-365*24*60*60/13;
       s4=s3+365*24*60*60/7+365*24*60*60/45-365*24*60*60/13;
       s5=s4+365*24*60*60/7+365*24*60*60/45-365*24*60*60/13;
       System.out.println("未来第1年的人口数为:"+s1);
       System.out.println("未来第2年的人口数为:"+s2);
       System.out.println("未来第3年的人口数为:"+s3);
       System.out.println("未来第4年的人口数为:"+s4);
       System.out.println("未来第5年的人口数为:"+s5);
       
	}

}

12

public class test12 {

	public static void main(String[] args) {
         double time=1+(35.0/60+40)/60.0;
         double s=24*1.6;
         double v=s/time;
         System.out.println(v);
	}

}

13

public class test13 {

	public static void main(String[] args) {
           double x,y;
           x=(44.5*0.55-50.2*5.9)/(3.4*0.55-50.2*2.1);
           y=(3.4*5.9-44.5*2.1)/(3.4*0.55-50.2*2.1);
           System.out.println("x="+x+","+"y="+y);
	}

}