The default constructor initializes method variables.
The default constructor has the same access as its class.
The default constructor invoked the no-arg constructor of the superclass.
If a class lacks a no-arg constructor, the compiler always creates a default constructor.
The compiler creates a default constructor only when there are no other constructors for the class.
第1题:
有如下程序: #include<iostream.h> Using namespace std; Class Demo { public: Demo(){ cout<<“default constructor\n”;} Demo(const Demo &x){ cont<<“copy constructor\n”;} }; Demo usercode(Demob){Demo c(b);return c;} int main() {
A.1和1
B.1和2
C.2和3
D.2和4
第2题:
A.class中的constructor不可省略
B.constructor在一个对象被new时执行
C.一个class只能定义一个constructor
D.constructor必须与class同名,但方法不能与class同名
第3题:
下列说法正确的有()
A.class中的constructor不可省略
B.constructor必须与class同名,但方法不能与class同名
C.constructor在一个对象被new时执行
D.一个class只能定义一个constructor
第4题:
Constructor with parameter const char* sourceString passed.
第5题:
以下程序的输出结果是_____。
include<iostream.h>
class object
{ private:
int val;
public:
object( ) ;
object(int i) ;
~object( ) ;};
object: :object( )
{ val=0;
cout < < "Default constructor for object" < < endl;}
object: :object(int i)
{ val=i;
cout < < "Constructor for object" < < val < < endl;}
object: :~object( )
{ cout < < "Destructor for object" < < val < < endl;}
class container{ private:
object one;
object two;
int data;
public:
container( ) ;
container(int i,int j,int k) ;
~container( ) ;};
container: :container( )
{ data=0;
cout < < "Default constructor for container" < < endl;}
container: :container(int i,int j,int k) :two(i) ,one(j)
{ data=k;
cout < < "Constructor for container" < < endl;}
container: :~container( )
{ cout < < "Destructor for container" < < endl;}
void main( )
{ container anObj(5,6,10) ;}
第6题:
有如下程序:#include<iostream>using namespace std;class test{private: int a;public: test(){cout<<"constructor"<<endl;} test(int a){cout<<a<<endl;} test(const test&_test) { a=_test.a; cout<<"copy constructor"<<en+dl; } ~test(){cout<<"destructor"<<endl;}};int main(){ test A(3); rerun 0;}运行时输出的结果是
A.3
B.constructor destructor
C.copy constructor destructor
D.3 destructor
第7题:
有如下程序: #include<iostream> using namespaee std; class Demo{ public: Demo( ){cout<<"default constructor\n";} Demo(const Demo &x){cout<<"copy constructor\n";} }; Derno userCore(DemoB) {Demo c(B) ;return c;} int main( ){ Demo a,d; cout<<"calling userCode( )\n"; d=userCode(A) ; return 0; } 执行上面程序的过程中,构造函数Demo( )和Demo(const Demo &x)被调用的次数分别为
A.1和1
B.1和2
C.2和3
D.2和4
第8题:
有如下程序: #include<iostream> using namespace std; class Demo { public: Demo(){ cout<<"default constructor\n";} Demo(const Demo & x){ cout<<"copy constructor\n":} }; Demo userCode(Demo b){DemoC(b);return c;} int main() { Demo a,d; cout<<"calling userCode()\n"; d=userCode(a); return 0; } 执行上面程序的过程中,构造函数Demo()和Demo(const Demo &x)被调用的次数分别是
A.1和1
B.1和2
C.2和3
D.2和4
第9题:
有如下程序: #include<iostream.h> using namespace std; class Demo { public: Demo(){ cont<<"default constructor\n";} Demo(const Demo &x){ cont<<"copy constructor\n";} }; Demo userCode(Demo b){Demo c(b);return c;} int main() { Demo a,d; cout<<"calling userCode()\n"; d=userCode(a); return 0; } 执行上面程序的过程中,构造函数Demo()和Demo(const Demo &x)被调用的次数分别是
A.1和1
B.1和2
C.2和3
D.2和4
第10题:
C# provides, by default a parameterless constructor. If I write a constructor that takes a string as a parameter, but want to keep the parameterless constructor. How many constructors should I write?
(C#提供默认构造函数(不带参数),如果我写了一个带有一个string类型参数的构造函数,但是又想保留不带参数的构造函数,那么我需要写多少个构造函数)