《java 语言程序设计》第1章编程练习

1.1

public class test {    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");    }}

1.2

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

1.3

public class test {    public static void main(String[] args) {        System.out.println("   J    A    V     V    A");        System.out.println("   J   A A    V   V    A A");        System.out.println("J  J  AAAAA    V V    AAAAA");        System.out.println(" JJ  A     A    V    A     A");    }}

1.4

public class test {    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");    }}

1.5

public class test {    public static void main(String[] args) {        double s = (9.5*4.5-2.5*3)/(45.5-3.5);        System.out.println(s);  //0.8392857142857143    }}

1.6

public class test {    public static void main(String[] args) {        int s=0;        for(int i=0; i<10; ++i) {            s+=i;        }        System.out.println(s);  //45    }}

1.7

public class test {    public static void main(String[] args) {        double pi = 0;        double t;        int m=1;        for(int i=1; i<12121358; i++) {            t=1.0/(2*i-1);            t*=m;            pi+=t;            m*=-1;        }        pi*=4;        System.out.println(pi); //3.1415927360890374    }}