How can a variable be used when its definition is bypassed?

Question

In my mind, always, definition means storage allocation.

In the following code, int i allocates a 4-byte (typically) storage on program stack and bind

Answer 1

Your code is fine. The variable lives wherever it would live had the goto not been there.

Note that there are situations where you can't jump over a declaration:

C++11 6.7 Declaration statement [stmt.dcl]

3 It is possible to transfer into a block, but not in a way that bypasses declarations with initialization. A program that jumps from a point where a variable with automatic storage duration is not in scope to a point where it is in scope is ill-formed unless the variable has scalar type, class type with a trivial default constructor and a trivial destructor, a cv-qualified version of one of these types, or an array of one of the preceding types and is declared without an initializer (8.5). [ Example:

void f()
{
    // ...
    goto lx;    // ill-formed: jump into scope of `a'
    // ...
ly:
    X a = 1;
    // ...
lx:
    goto ly;    // ok, jump implies destructor
                // call for `a' followed by construction
                // again immediately following label ly
}

—end example ]