Notes Hacks Grade
3.1-3.2 Notes 3.3-3.4 Hacks
3.3-3.4 Notes 3.3-3.4 Hacks
3.5-3.7 Notes 3.5-3.7 Hacks

Mathematical Expressions and Strings

Algorithms

A set of instructions that can accomplish a specific task

Three components of an algorithm

  1. Sequencing: Algorithms do task in the order of specification
  2. Selection: Helps choose two different outcomes based off a decision
  3. Iteration: If a condition is true, then the code can repeat

Two different ways algorithms can be represented

  1. Flowcharts: The steps of an algorithm are represented by shapes and arrows
  2. Pseudocode: A blend of human language and coding format

Arithmetic Operations

Basic Operations

Addition is represented by + Example: num1 = 2 + 1 which would make num1 = 3

Subtraction is represented by - Example: num1 = 2 - 1 which would make num1 = 1

Multiplication is represented by * Example: num1 = 2 * 1 which would make num1 = 2

Division is represented by / Example: num1 = 2 / 1 which would make num1 = 2

Remainder is represented by MOD in psuedo code (% in python) Example: num1 = 5 % 2 which would make num1 = 1

Order of operations applies

Variables

  • Numerical value stored in a variable
  • Value of another variable stored in a variable
  • Result of an operation stored in a variable
  • Result of a procedure call stored in a variable

Sequence of variables is important

String

A collection of characters. Characters can be anything from numbers, letters, spaces, etc.

Certain procedures can be used to affect string Examples: len() to find the length of string concat() returns the strings as a concatenation of multiple strings lower() to convert to lowercase