A: 10
B: 4
C: 20
D: 30
举一反三
- 请阅读下面程序public class ExampleStringBuffer{ public static void main (String[] args){ StringBuffer sb = new StringBuffer (“test”); System.out.println(“buffer = ”+sb); System.out.println(“length = ” + sb.length() ); }}程序运行结果中在"length ="后输出的值是（）。 A: 10 B: 20 C: 30 D: 4
- 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);}}
- 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
- 写出下面程序的输出结果 publicclassTestjava{ publicstaticvoidmain(String[]args){ Strings1="abcdefhij"; Strings2=""; char[]cs=s1.toCharArray(); for(inti=cs.length-1;i>=0;i--){ s2=s2+cs[i]; } System.out.println("输出的结果1:"+s2); StringBuffersb=newStringBuffer(s1); StringBuffersb2=sb.reverse(); System.out.println("输出的结果2:"+sb2); Strings3=myReverse(s1); System.out.println("输出的结果3:"+s3); } publicstaticStringmyReverse(Stringstr) { char[]arr=newchar[str.length()]; intpos=str.length(); for(intx=0;x[/i]
- 请阅读下列的程序publicclassExample01{publicstaticvoidmain(String[]args){intnum=127;byteb=num;System.out.println(b);}}程序的运行结果是()
内容
- 0
请看下面的程序代码,当 n 为( )值时,程序段将输出字符串 second。 [br][/br] switch(n) { [br][/br] case 0: System .out .println(“first”); [br][/br] case 1: [br][/br] case 2: System .out .println(“second”); break; [br][/br] default: System .out .println(“end”); [br][/br] }(2.0) A: 0 B: 1 C: 2 D: 以上都可以
- 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
下列程序编译并运行的结果为()publicclassTest{publicstaticvoidmain(String[]args){try{inti=1;System.out.println(i++);}finally{System.out.println(++i);}}}
- 3
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
- 4
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: