现有: public class Tester { public static void main (String[] args) { intx-5; Integer xl=x; Integer x2=x; int x3=new Integer(5); system..ut.print(x1.equals(x)); system..ut.print(xl==x); system..ut.print(x2.equals(xl)); system..ut.print(x2==xl); system..ut.print(x2==x3); system..ut.print(x2.equals(x3)); } } 结果为:()
第1题:
若有以下程序: #include <iostream> using namespaces std; class A { public: A (){} A (int i) { x1=i; } void dispa() { cout<<"xl="<<xl<<" , "; } private: int x1; }; class B : public A { public: B (){} B (int i):A(i+10) { x2=i; } void dispb() { dispa (); cout <<"x2="<<x2<<end1; } private: int x2; }; int main () { B b(2); b.dispb (): return 0; } 程序运行后的输出结果是( )。
A.x1=10,x2=2
B.x1=12,x2=10
C.x1=12,x2=2
D.x1=2,x2=2
第2题:
A. 3
B. 4
C.5
D.6
E.7
第3题:
现有:publicclassTester{publicstaticvoidmain(String[]args){intx-5;Integerxl=x;Integerx2=x;intx3=newInteger(5);system..ut.print(x1.equals(x));system..ut.print(xl==x);system..ut.print(x2.equals(xl));system..ut.print(x2==xl);system..ut.print(x2==x3);system..ut.print(x2.equals(x3));}}结果为:()
A.编译失败
B.falsefalsetruetruetruetrue
C.truetruetruetruetruetrue
D.falsefalsetruetruetruefalse
E.truefalsetruefalsefalsetrue
F.运行时异常被抛出
第4题:
程序: class TestApp{ public static void main (String[] args){ int x=6; if (x>l) System. out. println("x>l"); else if (x>5) System. out .println("x>5"); else if (x<10) System. out. println("x
第5题:
class Beta { public static void main(String [] args) { Integer x = new Integer(6) * 7; if (x != 42) { System.out.print("42 "); } else if (x 〈 new Integer(44-1)) { System.out.println("less"); } else { System.out.print("done"); } } } 结果是什么?()
第6题:
下列程序段执行后,x5的结果是______。 public class ex42 { public static void main(String[] args) { int xl = 8; int x2 = 12; int x3=7; int x4; int x5; x4 = x1 > x2 ? x1 : x2+ x1; x5 = x4 > x3 ? x4 : x3; System.out.println(x5); } }
A.11
B.20
C.10
D.12
第7题:
public class Test { public static void add3 (Integer i) { int val = i.intValue(); val += 3; i = new Integer(val); } public static void main(String args[]) { Integer i = new Integer(0); add3(i); System.out.println(i.intValue()); } } What is the result? ()
第8题:
interface A{
int x = 0;
}
class B{
int x =1;
}
class C extends B implements A {
public void pX(){
System.out.println(x);
}
public static void main(String[] args) {
new C().pX();
}
}
错误。在编译时会发生错误(错误描述不同的JVM 有不同的信息,意思就是未明确的
x 调用,两个x 都匹配(就象在同时import java.util 和java.sql 两个包时直接声明Date 一样)。
对于父类的变量,可以用super.x 来明确,而接口的属性默认隐含为 public static final.所以可
以通过A.x 来明确。
第9题:
现有: class Top { static int X=l; public Top() { x*=3; } } class Middle extends Top { public Middle() {x+=l; } public static void main(String [] args) { Middle m=new Middle(); System.out.println (x); } } 结果是什么?()
第10题:
public static void main( String[] args ) { Integer a = new Integer(10); Integer b = new Integer(10); Integer c = a; int d = 10; double e = 10.0; } Which three evaluate to true?()