Initializing variables in C

Question

I know that sometimes if you don\'t initialize an int, you will get a random number if you print the integer.

But initializing everything to zero seems

Answer 1

It's always good practice to initialize your variables, but sometimes it's not strictly necessary. Consider the following:

int a;
for (a = 0; a < 10; a++) { } // a is initialized later

or

void myfunc(int& num) {
  num = 10;
}

int a;
myfunc(&a); // myfunc sets, but does not read, the value in a

or

char a;
cin >> a; // perhaps the most common example in code of where
          // initialization isn't strictly necessary

These are just a couple of examples where it isn't strictly necessary to initialize a variable, since it's set later (but not accessed between declaration and initialization).

In general though, it doesn't hurt to always initialize your variables at declaration (and indeed, this is probably best practice).