《JAVA语言程序设计与数据结构》（基础篇）原书第11版

第一章（答案）

1.1

public class book1_1{public static void main (String[] args){System.out.print("Welcome to Java.");// print 不换行。System.out.println("Welcome to Science.");// println 换行。System.out.printf("Programming is fun.");// printf 类似与c语言中printf函数。}}

1.2

public class book1_2{public static void main (String[] args){for (int i = 0; i < 5; i ++)// 计数技巧System.out.println("Welcome to Java !");}}

1.3

public class book1_3 {public static void main(String[] args){System.out.printf(" JAVVA%n" + // '+' 字符串的拼接" J A AV VA A%n"+// %n 换行"J J AAAAAV VAAAAA%n" +" JJ AAVAA%n");}}

1.4

public class book1_4{public static void main(String[] args){String head1="a";// 创建 string 类型的数据 sString head2="a^2";String head3="a^3";System.out.printf("%-7s%-7s%-7s%n",head1,head2,head3);/* %-7s 从左往右占七个字符，不足右边空格补齐。%s 对应字符串。%d 对应整数。 */for(int i=1;i<5;i++)System.out.printf("%-7d%-7d%-7d%n",i,i*i,i*i*i);}}

1.5

public class book1_5{public static void main(String[] args){double result = (9.5 * 4.5 - 2.5 * 3.0) / (45.5 - 3.5);System.out.println(result);}}

1.6

public class book1_6{public static void main(String[] args){int num = 0;// 标识符的使用。for (int i = 0; i < 10; i++)num = num + i ;System.out.println(num);}}

1.7

public class book1_7{public static void main(String[] args){approximate(7);approximate(8);}public static void approximate(int n){// 方法：【修饰符列表】返回值类型 方法名（形式参数列表）// void 严格无 return语句。double fractional = 1.0; // 报错类型：不兼容的类型: 意外的返回值double sum = 0.0;for(int i = 1; i < n; i++){sum += fractional * 1.0 / (2 * i - 1);fractional *= -1.0;}System.out.println(4.0*sum);}}

1.8

public class book1_8 {public static void main(String[] args) {// Display areaSystem.out.println(5.5 * 5.5 * 3.14159);// Display perimeterSystem.out.println(2 * 5.5 * 3.14159);}}

1.9

public class book1_9 {public static void main(String[] args) {// Display areaSystem.out.println(4.5 * 7.9);// Display perimeterSystem.out.println( 2 * ( 4.5 + 7.9));}}

1.10

public class book1_10 {public static void main(String[] args) {System.out.println( (14 / 45.5) * 60 / 1.6);}}

1.11

public class book1_11 {public static void main(String[] args){double base = 312032486;int secnum = 365*24*3600;for(int i=1;i<6;i++){base = base + secnum / 7.0 - secnum / 13.0 + secnum / 45.0;System.out.println( (int)base + " in " + i + " yeas ！");}}}

1.12

public class book1_12 {public static void main(String[] args) {System.out.println(24 / (1 + (40 + 35.0 / 60) / 60) * 1.6);}}

1.13

public class Exercise01_13 {public static void main(String[] args) {double a=3.4,b=50.2,e=44.5;double c=2.1,d=0.55,f=5.9;System.out.println("x is " + ( e * d - b * f) / ( a * d - b * c ) );System.out.println("y is " + ( a * f - e * c) / ( a * d - b * c ) );}}

Java小白入门学习笔记，欢迎大佬评论……