the default constructor is to provide a no compiler implicit constructor, only when the class does not define any constructors is valid, but you customize a constructor, in the circumstance that does not have to set the default parameters, parents will be looking for children a no-parameter constructor (because of the impact of function overloading overloaded),
Then how to call?
Here are two kinds of schemes
Set the default parameters of the first: is it about
For example the following code can

 # include 
using namespace std; 
The class father 
{
Private: 
Int years; 
Int height; 
Public: 
Father (int years=0, int height=0) : years (years), height (height) 
{
Cout<& lt;" Father constructor "& lt; } 
Father (const father & amp; F) 
{
This - & gt; Years=f.y ears; 
This - & gt; Height=f.h eight; 
Cout<& lt;" The copy constructor "& lt; } 
~ the father () 
{
Cout<& lt;" Destructor "& lt; } 
Void init (int & amp; A, int & amp; B) 
{
Years=a; 
Height=b; 
Cout<& lt;" Father init succeed "& lt; } 
Void the show () 
{
Cout<& lt;" Father years is "& lt; } 
Void the get () 
{
Cout<& lt;" Difference son money "& lt; } 
}; 
The class son: public father 
{
Public: 
Void the get () 
{
Cout<& lt;" The difference money "& lt; } 
Void the sum () 
{
Cout<& lt;" The sum "& lt; } 
}; 
Int main () 
{
Son s1. 
//father * f1=& amp; S1. 
//s1. The get (); 
return 0; 
} 

this is the figure

The second set to subclass a structure, and in its designated the superclass constructor
And what is the difference between this change

 son (int int a, c, e, d) : father (100200) 
{

Cout<& lt;" Son Constructed \ n "; 
} 

 int main () 
{
Son s1 (1, 2); 
return 0; 
} 

The results figure

Finally long-winded, I compile environment for GCC

Thank you. Thank you for your enthusiastic help

CodePudding user response:

refer to the second floor @ contradict response:

well, is it, what is not, forgive my hand shaking, what's wrong or questions welcome to discuss the

I added an int behind the object weight=0, the program is ok,
In addition, I still don't understand where I went wrong
Can I ask you for me

CodePudding user response:

reference 4 floor qq_45805535 response:

Quote: refer to the second floor of the @ contradict reply:

well, is it, what is not, forgive my hand shaking, what's wrong or questions welcome to discuss the

I added an int behind the object weight=0, the program is ok,
In addition, I still don't understand where I went wrong
Could I ask you, please

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