Q.Program 7-14: Program to access any variable outside the function

Variable Scope: The Concept

Imagine you're in a large house with many rooms. In the kitchen, there's a knife that only the cook uses. In the study, there's a pen that only the writer touches. The knife exists, but you can't reach it from the study — it's out of scope. The pen exists, but you can't grab it from the kitchen.

That's variable scope in programming. A variable is "visible" (accessible) only within a certain region of your code. Outside that region, the variable simply doesn't exist — as if it were never declared.

The Precise Statement

Variable scope is the region of a program where a declared variable can be referenced by name. Outside that region, the name is not bound to that variable — using it causes an error (or refers to a different variable entirely).

Scope is determined by where you declare the variable. The most common rule: a variable is accessible from the line it's declared down to the end of the block (the { } pair) that contains it.

The Two Main Kinds of Scope

1. Local Scope (Inside a Function/Block)

def greet():
    message = "Hello!"   # message is local to greet()
    print(message)       # works fine

greet()                  # prints "Hello!"
print(message)           # ERROR: message is not defined here

message lives only inside greet(). Once the function ends, the variable is destroyed. This is local scope — the variable belongs to that function alone.

2. Global Scope (Outside All Functions)

name = "Alice"           # name is global

def say_hello():
    print(name)          # works — global variables are visible inside functions

say_hello()              # prints "Alice"
print(name)              # also works — we're in the same global scope

A variable declared at the top level of your program (not inside any function or block) is global. It's visible everywhere — inside functions, inside loops, everywhere.

x = 10
def change():
    x = 5          # This creates a NEW local x, does NOT touch the global x

change()
print(x)           # Still 10, not 5

Why Scope Matters …