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In the previous class, you had learned about introduction to coding. In this class, you are going to
learn more about coding.
What are Variables?
Variable is a name given to a location in the memory, to store values or
data. For example, you must have seen your mother naming boxes in the
kitchen. That box has a little storage capacity and your mother gave it a SUGAR SALT
name such as, salt, sugar, tea, etc.
Variables are also similar to a box or a packet. These packets can be
named, referenced and used to perform various mathematical operations.
So, a variable has a name (to refer to it), a type (kind of data it store and its size) and a value (data).
Usually variables are used to hold one or more values, result of calculations, etc.
Scope of a Variable
While creating a variable, you should also remember the limits of its usage. For example, the boxes
that your mother named, can be used in the kitchen and rarely outside of the kitchen. Similarly, a
variable can also be used in specific areas of a code, known as scope of a variable.
The scope or accessibility of the variables defined in a program depends where you have declared it
in each program. Variable defined outside the scope cannot be accessed.
Naming Variables
Every variable in a program is unique and you need to allocate
variable a unique name. You cannot use the same name of a variable
more than once.
Variable name acts as an identifier for that variable and suggest the
information which it contains.
In Covid-19 pandemic time, Avi Schiffmann, a teenager, coded one of the most
visited website across the globe ‘ ncov2019.live’, to monitor COVID-19.
Example: If variable ‘x’ stores value 3, variable ‘y’ stores value 3. When we perform addition
operation on ‘x’ and ‘y’, we will get the output as ‘6’.
Note: Variable is created, when you assign a value to it.
Rules for Naming a Variable In Python:
Name your variables in such a way that it describes its purpose.
Variable name must begin with a letter or an underscore and can range from 1 to 255 characters.
No special character or spaces are allowed.
Uppercase and lowercase characters are distinct.
Keywords (reserved words) cannot be used as a variable.
64 DigiCode AI-VII

