Default variable value

Question

If I don\'t assign a value to a variable when I declare it, does it default to zero or just whatever was previously in the memory?

e.g.

float x;
         


        

Answer 1

It depends on the lifetime of the variable. Variables with static lifetime are always zero-initialized before program start-up: zero-initialization for basic types, enums and pointers is the same as if you'd assigned 0, appropriately converted to the type, to it. This occurs even if the variable has a constructor, before the constructor is called.