Nov 10, 2019

# Chapter Overview

• Basic data types
• Integer
• Real number
• Char
• String
• Boolean
• Programming
• Rules in naming variable
• Sequence
• Selection
• Iteration
• Totalling
• Counting

## 11.1 Basic data types

INTEGER
A positive or negative whole number that can be used with mathematical operators.

REAL
number with a fractional part, that can be used with mathematical operators.
Not all programming languages distinguish between real numbers and integers. For example, JavaScript makes no distinction but Python does.

``````Integer = int(25) // Declare an integer with the value of 25
Real = float(25) // Declare a real number with the value of 25.0
``````

CHAR
single character.

``````Char = 'A'
Char = "A"
``````

STRING
A string variable has several characters in length. String vary in length and may even have no characters. The characters can be lettersand/or digits and/or any other printable symbols. For example:

``````exam_name = 'CIE'
subject_code = '0478'
``````

BOOLEAN
A boolean variable can have only two values: TRUE or FALSE

``````pass_CIE_exam_with_help_of_SCIEprogrammer = TRUE
``````

## 11.2 Programming

RULES IN NAMING VARIABLES

• Case-sensitive (number1 is different from Number1)
• Can contain numbers, letters and underscore
• CAN NOT be the same as Python Reserved words
E.g. max, min, sum
Otherwise, you’ll lose mark in CIE EXAM !

SEQUENCE
Statements that runs one by one in order.

``````first_num = int(input('Enter the first whole number:'))
second_num = int(input('Enter the second whole number:'))
total = first_num + second_num
print('The sum equals', total)
``````

SELECTION
Running the following statements depends on whether the criteria given is satisfied or not. In Python we use IF statement:

``````if grade == 100:
print('Excellent! You got TOP IN THE WORLD in computer science.')
print('Great! You can improve by spending more effort.')
else:
print('Oops! You need more hard work.')
``````

Difference between single equal sign (=) and double equal signs (==)

• Single Equal Sign means to assign value or content or variable on right to the variable on the left
• It means ‘

#### Astatine-213

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