C ++中的构造函数行为

Question

How is this possible??
test t2=50 ??? as t2 is object a.....so how can it be equal ti an integer using visual studio 2008

class test
{
public :
 int a,b;
 test(int x=0,int y=0)
 {
  a=x;
  b=y;
 }
};


void g()
{
 test t1=test(10,20);
 test t2=50;
 cout<<t1.a<<":"<<t1.b<<endl;
 cout<<t2.a<<":"<<t2.b<<endl;
}

int main()
{
 g();
 system("pause");
}

Answer 1

Since your constructor is not defined as explicit the compiler uses the constructor defined in test class to create a test object by passing the integer argument to the constructor (Parameter x ). To avoid this declare the constructor as explicit .