Parameters & Scoping

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Parameters & Scoping#

This modified example introduces a couple of key concepts for working with functions:

  • Inside a function, the arguments are assigned to local variables, or placeholder variables. These local variables are called parameters.

    • Key term: parameter

  • The name of the parameter inside the function is separated or isolated from the name outside the function. This separation of namespaces is called scoping.

    • Key term: scoping

Python Example#

# assign x variable
x = 1

# function definition
def print_number(x):
 print(x)

# print x variable
print(x)

# call named function
print_number(2)

The value of x in the first line of this program has nothing to do with the purpose x is serving in the function definition.

In short, the placeholder variables (or parameters) we use inside the function definition are separated or isolated from any instance where a variable or parameter with the same name is used outside the function definition.

Click here to learn more about scope in Python, via W3Schools.
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