Calculations

on the data

Make a decision

variables

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a variable is a name for a container¹ that stores a value

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¹really a location in the computer memory

variables

data structures

binary

All data in a computer is stored as a binary number. Depending on context, the binary value 11100101 can be interpreted by the computer as

• the positive integer 229
• the negative integer -27
• the character σ (sigma)

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• the red level of a pixel (229 out of 255)

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• an instruction to the processor (e.g. add two numbers)
• ⋮ ⋮ ⋮

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Calculations

on the data

calculations

Make a decision

Step-by-Step (top-to-bottom)

algorithm

if with else ifs

looping

(definite loop)

looping

(indefinite loop)

bubble sort algorithm

number guessing algorithm