java2实用教程(第三版)第五章习题答案(耿祥义).doc

public class T5_1 public static void main(String args) /已定义好的字符串变量String s = Hello World !;System.out.println(s);s = s.toUpperCase();System.out.println(s);s = s.toLowerCase();System.out.println(s);/通过键盘输入字符串/*System.out.println(args0);args0 = args0.toUpperCase();System.out.println(args0);args0 = args0.toLowerCase();System.out.println(args0);*/public class T5_2 public static void main(String args) /通过键盘输入两个字符串 ,在java时注意在敲入java StringCat时在后面加上两个字符串。eg.java StringCat Hello China;/*System.out.println(string1 :+args0);System.out.println(string2 :+args1);args0 = args0.concat(args1);System.out.println(concat string :+args0);*/已定义的字符串 String s1 = Hello ;String s2 = China!;System.out.println(s1 = +s1);System.out.println(s2 = +s2);s1 = s1.concat(s2);System.out.println(concat.);System.out.println(s1 = +s1);System.out.println(s2 = +s2);public class T5_3 public static void main(String args) String s = 中国科学技术大学;char a = s.charAt(2),b = s.charAt(6);System.out.print(a);System.out.println(b);import java.util.*;public class T5_4 public static void main(String args) int a = 23,67,89,90,-987;double b = 12.89,90.87,34,678.987,-98.78,0.89;Arrays.sort(a);Arrays.sort(b,1,4);for(int i=0;i=4;i+) System.out.print(ai+,);System.out.println();for(int i=0;ib.length;i+) System.out.print(bi+,);System.out.println();public class T5_5 public static void main(String args) char a1 = a,b,c,d,e,f,b1 = 1,2,3,4,5,6;System.arraycopy(a1,0,b1,1,a1.length-1);System.out.println(new String(a1);System.out.println(new String(b1);byte a2 = 97,98,99,100,101,102,b2 = 65,67,68,69,70,71;System.arraycopy(b2,0,a2,