What's the difference between initializing a variable in these constructors? And how to put a constructor as default?

Is there any difference in initializing a variable in any of these forms of constructors? And how do I put a constructor as default ( default ) in a class that has more than one constructor?

Builder 1:

class Teste
{
private:
    int valor1, valor2;
    float valor3;
public:
    Teste(void) : valor1(0), valor2(0), valor3(0.f) {}
};

Builder 2:

class Teste
{
private:
     int valor1, valor2;
     float valor3;
public:
     Teste(void)
     { 
         valor1 = 0;
         valor2 = 0;
         valor3 = 0.f;
     }
};

I am currently preferring to use constructor method 1 because I find it cleaner, changes into something?