A: =null
B: =null0
C: =null1
D: =nullM
举一反三
- 5、下列程序的运行结果是（）。public static void main( String[] args ){StringBuffer sb = new StringBuffer();sb.append("qq").append("ww");show( sb, "ss" );System.out.println( sb.length() );}public void show( StringBuffer sb, String str ){sb.append( str );} A: 4 B: 2 C: 6 D: 0
- public class Example { String str = new String("Java"); StringBuffer sb = new StringBuffer("C#"); public void strcat(String str, StringBuffer sb) { str = str + " study"; sb = sb.append(" exam"); } public static void main(String args[]) { Example ex = new Example(); ex.strcat(ex.str, ex.sb); System.out.println(ex.str); System.out.println(ex.sb); }}程序的输出结果是：______
- 分析下面的Java程序段,编译运行后的输出结果是( )。public class Test {public void changeString(StringBuffer sb) {sb.append("stringbuffer2");}public static void main(String[] args) {Test a = new Test();StringBuffer sb = new StringBuffer("stringbuffer1");a.changeString(sb);System.out.println("sb = " + sb);}} A: sb = stringbuffer2stringbuffer1 B: sb = stringbuffer1 C: sb = stringbuffer2 D: sb = stringbuffer1stringbuffer2
- class Test { public static void main(String[] args) { StringBuffer sb = new StringBuffer("jack"); sb.append(true); sb.append('a'); sb.append(97).append(34.0).append(new char[]{'A','B'}); // 链式编程 System.out.println( sb.toString() ); // 输出缓冲区的中文本数据 sb = new StringBuffer("jack"); sb.insert( 2, "java" ); System.out.println( sb.toString() ); } } A: jacktruea9734.0AB jjavaack B: jacktruea9734.0AB jajavack C: jacktrueaa34.0AB jajavack D: jacktruea9734AB jajavack
- 下列程序的运行结果是（）public class Test {public static void main(String[] args) {String str = NULL;System.out.println(str);}} A:
内容
- 0
class Test { public static void main(String[] args) { StringBuffer sb = new StringBuffer("abcd"); sb.reverse(); System.out.println( sb.toString() ); } } 代码的输出结果是： dcba
- 1
public class StringBufferTest {public static void main(String[] args) {StringBuffer sb=new StringBuffer("aynu,aynu");sb.deleteCharAt(4);System.out.println(sb);//第1空sb.delete(4, 8);System.out.println(sb);//第2空}}
- 2
（6-9）请阅读程序，写出程序运行结果。 class Phone{ private String name; private int price; public Phone(String name, int price) { this.name = name; this.price = price; } public String toString() { return ""+this.price; } } public class PhoneDemo { public static void main(String[] args) { StringBuffer sb=new StringBuffer(); Phone [] list=new Phone[3]; list[0]=new Phone("华为",3000); list[1]=new Phone("小米8",4000); list[2]=new Phone("vivo R10",2300); for(Phone p:list) sb.append(p); System.out.println(sb.toString()); } }
- 3
下列程序对字符串进行操作public class Test{public static void main(String[ ] args){StringBuffer sb = new StringBuffer("保护环境");______1______("责任");//追加字符串System.out.println(sb); ______2______(4,"大家的");//插入字符串System.out.println(sb);______3______(4,7);//删除字符串System.out.println(sb);}}
- 4
下面的程序功能是实现字符串大小写的转换并倒序输出。public static void Main(string[] args){ string str = "HelloWorld"; ______ sb=new StringBuilder(); for (int i = 0; i &lt; str.______ ; i++) { if (str[i] >= 'a' && str[i] <= 'z') { sb.Append( str[i].ToString().ToUpper()); } else { sb.Append( str[i].ToString().______ ()); } } Console.WriteLine(sb.ToString()); Console.ReadKey();}[/i][/i][/i][/i]