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
举一反三
- 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("hello world"); sb.delete(6,sb.length()); System.out.println( sb.toString() ); } } A: Hello w B: Hello C: Hello worl
- 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}}
- 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);}}
- class Test { public static void main(String[] args) { StringBuffer sb = new StringBuffer("hello world"); sb.replace(6, sb.length(), "java"); System.out.println( sb.toString() ); } } 选择正确的运行结果 A: hello javad B: hellojava C: hello java