int a = 0 and int a(0) differences [duplicate]

Question

Possible Duplicate:
Is there a difference in C++ between copy initialization and direct initialization?

I just started to learn C++.

To initialize a variable with a value, I came across

int a = 0; 

and

int a(0); 

This confuses me a lot. May I know which is the best way?

Answer 1

int a = 0; and int a(0); make no difference in the machine generated code. They are the same.

Following is the assembly code generated in Visual Studio

int a = 10;   // mov dword ptr [a],0Ah   int b(10);    // mov dword ptr [b],0Ah   

Answer 2

They're both the same, so there really is no one "best way".

I personally use

int a = 0; 

because I find it more clear and it's more widely used in practice.

This applies to your code, where the type is int. For class-types, the first is copy-initialization, whereas the other is direct-initialization, so in that case it would make a difference.