Global variables and local variables in the C language

1. Illustrate by two diagrams

(1) Global variables

Run successfully

(2) Local variables

Failed to run

As you know, repeating the definition of a variable in the main function will cause an error.

But why is the definition above not an error?

concluded that:

(1) Global variable definition and declaration are different

(2) There is no difference between a local variable definition and a declaration

Description

For example , int A: Is the definition, and int a = 1 is an assignment!

Look at the function!

Success, the success of the verification!

Look at the global variables!

Verified successfully!

Global variables and local variables in the C language