JAVA认证：147道SCJP考试试题精解

JAVA认证：147道 SCJP考试试题精解Leading the way in IT testing and certification tools,Question No:1Given:1.public class test(2.public static void main(String args)3.inti=OxFFFFFFFl;4.int j=i;5.6.7.)What is the decimal value of j at line 5?A.0B.1C.14D.-15E.An error at line 3 causes compilation to fail.F.An error at line 4 causes compilation to fail.Answer:CQuestion No:2Given:Integer i=new Integer(42);Long 1 =new Long(42);Double d=new Double(42.0);Which two expressions evaluate to True?(Choose Two)A.(i=1)B.(i=d)C.(d=1)D.(i.equals(d)E.(d.equals(i)F.(i.equals(42)Answer:D,EQuestion No:3Exhibit:1.public class test(2.private static int j=0;3.4.private static boolean methodB(int k)(5.j+=k;6.return true;6.)7.8.public static void methodA(int i)9.boolean b:10.b=i<10 I methodB(4);l l.b=i<1011 methodB(8);12.)13.14.public static void main(String args(15.methodA(0);16.system.out.println(j);17.)18.)What is the result?A.The program prints A”B.The program prints 4”C.The program prints C”D.The program pren:1.public class Foo 2.public static void main(String args)3.StringBuffer a=new StringBuffer(66An);4.StringBuffer b=new StringBuffer(B);5.operate(a,b);6.system.out.printlna+b;7.)8.static void operate(StringBuffer x,StringBuffer y)9.x.append y;10.y=x;H.)12.What is the result?A.The code compiles and printsB.The code compiles and prints A,A”.C.The code compiles and printsD.The code compiles and prints AB,B”.E.The code compiles and prints AB,AB”.F.The code does not compile because cannot be overloaded forStringBuffer.Answer:DQuestion No:6Exhibit:1.Public class test(2.Public static void stringReplace(String text)(3.Text=text.replace(J ,4.)5.6.public static void bufferReplace(StringBuffer text)(7.text=text.append(“C”)8.)9.10.public static void main(String args)(11.String textString=new String(java);12.StringBuffer text BufferString=new StringBuffer(“java”)；13.14.stringReplace(textString);15.BufferReplace(textBuffer);16.17.System.out.printin(textString+textBuffer);18.19.)What is the output?Answer:javajavaCQuestion No:7Exhibit:1.public class test 2.public static void add3(Integer i)3.int val=i.intValue();4.val+=3;5.i=new Integer(val);6.7.8.public static void main(String args I J)9.Integer i=new Integer(0);10.add3(i);11.system.out.println(i.intValue();12.13.)What is the result?A.Compilation will fail.B.The program prints 0.C.The program prints 3”.D.Compilation will succeed but an exception will be thrown at line 3.Answer:BQuestion No:8Given:1.public class ConstOver 2.public ConstOver(int x,int y,int z)3.)4.)Which two overload the ConstOver constructor?(Choose Two)A.ConstOver()B.Protected int ConstOver()C.Private ConstOver(int z,int y,byte x)D.Public Object ConstOver(int x,int y,int z)E.Public void ConstOver(byte x,byte y,byte z)Answer:A,CQuestion No:9Given:1.public class MethodOver 2.public void setVar(int a,int b,float c)3.)4.)Which two overload the setVar method?(Choose Two)A.Private void setVar(int a,float c,int b)B.Protected void setVar(int a,int b,float c)C.Public int setVar(int a,float c,int b)(return a;)D.Public int setVar(int a,int b,float c)(return a;)E.Protected float setVar(int a,int b,floatc)(return c;)Answer:A,CQuestion No:10Given:1.class BaseClass 2.Private float x=l.Of;3.protected float getVar()(return x;)4.)5.class Subclass extends BaseClass(6.private float x=2.0f;7./insert code here8.)Which two are valid examples of method ovemding?(Choose Two)A.Float getVar()return x;B.Public float getVar()return x;C.Float double getVar()return x;D.Public float getVar()return x;E.Public float getVar(float f)return f;Answer:B,DQuestion No:11Which two demonstrate an is a relationship?(Choose Two)A.public interface Person public class Employee extends Person)B.public interface Shape public class Employee extends Shape C.public interface Color public class Employee extends Color D.public class Species public class Animal(private Species species;)E.interface Component Class Container implements Component(Private Component children;)Answer:D,EQuestion No:12Which statement is true?A.An anonymous inner class may be declared as final.B.An anonymous inner class can be declared as private.C.An anonymous inner class can implement multiple interfaces.D.An anonymous inner class can access final variables in any enclosing scope.E.Construction of an instance of a static inner class requires an instance of theenclosing outer class.Answer:DQuestion No 13Given:1.package foo;2.3.public class Outer(4.public static class Inner(5.)6.)Which statement is true?A.An instance of the Inner class can be constructed with“new Outer.Inner()”B.An instance of the inner class cannot be constructed outside of package foo.C.An instance of the inner class can only be constructed from within the outerclass.D.From within the package bar,an instance of the inner class can be constructedwith“new inner。Answer:AQuestion No 14Exhibit:1.public class enclosingone(2.public class insideone3.)4.public class inertest(5.public static void main(stringargs)(6.enclosingone eo=new enclosingone