Difference between Local Variable and Global Variable

The primary difference between local variables and global variables is that local variables are variables that are declared within a specific scope, such as inside a function or a block of code. Global variables, on the other hand, are variables that are declared outside of any function or block of code.

In this article, we will discuss the main differences between local variables and global variables.

Local variables are only accessible within that particular scope and are not visible or usable outside of it. Local variables have a limited lifespan and are created when the scope in which they are defined is entered, and they are destroyed when the scope is exited. Each time the scope is entered, a new instance of the local variable is created.

Global variables have a longer lifespan compared to local variables and are created when the program starts and destroyed when the program terminates. Unlike local variables, there is only one instance of a global variable throughout the program.

Local Variable vs Global Variable

Now, let’s compare the differences between local variables and global variables in the following table:

	Local Variables	Global Variables
Declaration	Declared inside a specific scope	Declared outside any function or block
Scope	Limited to the specific scope	Accessible from anywhere in the program
Visibility	Not visible outside the scope	Visible and usable throughout the program
Lifespan	Created when the scope is entered.	Destroyed when the scope is exited
	Destroyed when a program terminates	Destroyed when program terminates
Instances	Multiple instances can exist	Only one instance exists
Naming conflicts	No conflict outside the scope	Possible conflicts if names clash