// Program 1:public class Test { public static void main(String[] arg

1.分析以下代码 // Program 1public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(((A)a1).equals((A)a2)); }} class A { int x; public boolean equals(A a) { return this.x == a.x; }} // Program 2public class Test { public static void main(String[] args) { A a1 = new A(); A a2 = new A(); System.out.println(a1.equals(a2)); }} class A { int x; public boolean equals(A a) { return this.x == a.x; }}选项： A:Program 1输出 true 并且 Program 2 输出 true; B:Program 1 输出 false并且Program 2 输出 true; C:Program 1 输出 true并且Program 2 输出 false; D:Program 1 输出 false并且Program 2 输出 false

2.Analyze the following code. ( )// Program 1:Public class Test {Public static void main(String] args) {Object a1 = new A();Object a2 = new A();System.out.println(a1.equals(a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x == a .x;}}// Program 2:Public class Test {Public static void main(String] args) {A a1 = new A();A a2 = new A();System.out.println(a1.equals(a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x ==a .x;} } 选项： A:Program 1 displays true and Program 2 displays true B:Program 1 displays false and Program 2 displays true C:Program 1 displays true and Program 2 displays false D:Program 1 displays false and Program 2 displays false

3. 单选题Analyze the following code. ( )// Program 1:Public class Test {Public static void main(String] args) {Object a1 = new A();Object a2 = new A();System.out.println(a1.equals(a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x == a点x;}}// Program 2:Public class Test {Public static void main(String] args) {A a1 = new A();A a2 = new A();System.out.println(a1.equals(a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x ==a点x;}} 选项： A:Program 1 displays true and Program 2 displays true B:Program 1 displays false and Program 2 displays true C:Program 1 displays true and Program 2 displays false D:Program 1 displays false and Program 2 displays false

4.Analyze the following code. ( )// Program 1Public class Test {Public static void main(String] args) {Object a1 = new A();Object a2 = new A();System.out.println(((A)a1).equals((A)a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x == a .x;}}// Program 2Public class Test {Public static void main(String] args) {A a1 = new A();A a2 = new A();System.out.println(a1.equals(a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x == a .x;} } 选项： A:Program 1 displays true and Program 2 displays true B:Program 1 displays false and Program 2 displays true C:Program 1 displays true and Program 2 displays false D:Program 1 displays false and Program 2 displays false

5. 单选题Analyze the following code. ( )// Program 1Public class Test {Public static void main(String] args) {Object a1 = new A();Object a2 = new A();System.out.println(((A)a1).equals((A)a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x == a点x;}}// Program 2Public class Test {Public static void main(String] args) {A a1 = new A();A a2 = new A();System.out.println(a1.equals(a2));}}Class A {Int x;Public boolean equals(A a) {Return this.x == a点x;}} 选项： A:Program 1 displays true and Program 2 displays true B:Program 1 displays false and Program 2 displays true C:Program 1 displays true and Program 2 displays false D:Program 1 displays false and Program 2 displays false

6. 以下代码的输出是什么: public class Test { public static void main(String[] args) { Object o1 = new Object(); Object o2 = new Object(); System.out.print((o1 == o2) + " " + (o1.equals(o2))); }}选项： A:false false; B: true true; C:false true; D:true false

7.如下代码的输出是( )。public class Test { public static void main(String[] args) { Object o1 = new Object(); Object o2 = new Object(); System.out.print((o1 == o2) + " " + (o1.equals(o2))); }} 选项： A、false false B、true true C、false true D、true false

false B、true
true C、false
true D、true
false">8.下列代码的输出结果为:(). public class Test { public static void main(String[] args) { Object o1 = new Object(); Object o2 = new Object(); System.out.print((o1 == o2) + " " + (o1.equals(o2))); }} 选项： A、false
false B、true
true C、false
true D、true
false

false B、true
true C、false
true D、true
false">9.以下代码的输出结果为:()public class Test { public static void main(String[] args) { Object o1 = new Object(); Object o2 = new Object(); System.out.print((o1 == o2) + " " + (o1.equals(o2))); } 选项： A、false
false B、true
true C、false
true D、true
false

10.如下代码的输出是（）。 public class Test { public static void main(String] args) { Object o1 = new Object(); Object o2 = new Object(); System.out.print((o1 == o2) + " " + (o1.equals(o2))); } }A. false falseB. true trueC. false trueD. true false 选项： A:正确 B:错误

11.下列程序中构造了一个SET并且调用其方法add（），输出结果是（___________）public class A{public int hashCode（）{return 1；}public Boolean equals（Object b）{return true}public static void main（String args[]）{ Set set=new HashSet（）；set.add(new A());set.add(new A());set.add(new A());System.out.println(set.size());}}

12.下面程序的运行结果是（） public class Test { public static void main(String[] args) { String s1 = new String("Hello"); String s2 = new String("Hello"); boolean b1 = s1.equals(s2); boolean b2 = s1 == s2; System.out.println(b1 + ", " + b2); }}选项： A:false, true; B:true, false; C: false, false; D: true, true

13.以下程序的输出结果是().public class Test{public static void main(String args[]){int x[]=new int [8];System.out.println(x[1]);}}

14.下列代码的执行结果是( )。 public class Test public static void main String args[]) String s1＝new String("welcome")； String s2=new String("welcome")； System．out．println(s1＝=s2)； System．out．println(s1．equals(s2))；选项： A、false，false B、false，true C、true，true D、true，false

15.下列代码的执行结果是（）。 public class Test { public static void main(String[] args) { String s1=new String("hello"); String s2=new String("hello"); System.out.println(s1==s2); System.out.println(s1.equals(s2)); } } A: true false B: true true C: false true D: false false

16.下列代码的执行结果是______ public class Test5{ public static void main(String args[]){ String s1=new String("hello"); String s2=new String("hello"); System.out.println(s1==s2); System.out.println(s1.equals(s2)); } } A: true false B: true true C: false true D: false false

17.public class Test { public static void main(String[] args) { String s1 = new String("abc"); String s2 = new String("abc"); boolean b = s1.equals(s2); System.out.println(b); } } 上面程序的输出结果为。

18.下列语句输出结果为( )。public class test{public static void main(String args []){String s1=new String("How");String s2=new String("How");System.out. println(!(s1 ==s2));} 选项： A、false B、true C、1 D、0

19.下列代码的执行结果是( )。 public class Test{ public static void main String args[]){ String s1＝new String("welcome")； String s2=new String("welcome")； System．out．println(s1＝=s2)； System．out．println(s1．equals(s2))； } } A．false，falseB．false，trueC．true，trueD．true，false

20. 程序阅读填空题编译运行如下代码，输出结果是。public class A{ private static int x=100; public static void main(String args[]){ A a1=new A(); a1.x++; A a2=new A(); a2.x++; A.x--; System.out.println("x="+x); }}

21.下列代码的执行结果是______ public class Test5{ public static void main(String args[]){ String s1=new String("hello"); String s2=new String("hello"); System.out.println(s1==s2); System.out.println(s1.equals(s2)); } } 选项： A、true false B、true true C、false true D、false false

22.下列代码的运行结果是：class A1{ public A1(){ System.out.println("A1"); }}class A2 extends A1{ public A2(){ System.out.println("A2"); }}public class A extends A2{ public A(){ System.out.println("A"); } public static void main(String[] args) { A a=new A(); }}选项： A:A1A2A; B:A; C:AA2A1; D:A2; E:A1

23.下列程序中构造了一个SET并且调用其方法add（），输出结果是_________import java.util.*;public class Example{public int hashCode(){return 1;}public boolean equals(Object b){return true;}public static void main(String args[]){Set set=new HashSet();set.add(new Example());set.add(new Example());set.add(new Example());System.out.println(set.size());}}