Getting Started

Welcome to Common Pseudocode! This guide will help you understand the fundamentals of the language.

General Notes

Common Pseudocode works like JavaScript, where each new line is treated as a statement with an implicit “semicolon” at the end. There’s no need for explicit statement terminators.

Indentation is done Python-style, but without the need for the : at the end of parent statements. Proper indentation is crucial for defining code blocks.

Your First Program

Let’s start with a simple “Hello World” program:

output "Hello, World!"

That’s it! The output statement displays text to the user.

Comments

Comments help document your code and are ignored during execution.

Single-line comments:

// This is a single-line comment
x = 5  // This is an inline comment

Multi-line comments:

/*
This is a multi-line comment
that spans multiple lines
*/
x = 10

Variables and Assignment

Declare a variable without an initial value:

define variableName

Assign a value to a variable:

newNumber = 7
currentNumber = newNumber

Example with define:

define counter
define userName
define isValid

counter = 0
userName = "John"
isValid = true

Data Types

Common Pseudocode supports several basic data types:

Numbers

age = 25
price = 19.99

Strings

Strings can be enclosed in single quotes, double quotes, or backticks:

name = "John"
greeting = 'Hello'
message = `Welcome!`

Multi-line strings:

`
This is a multiline string
that spans multiple lines
`

Or using triple quotes:

"""
This is also a multiline string
"""

Booleans

isActive = true
isComplete = false

Note: true, True, and TRUE are all valid (same for false).

Type Conversion

Convert between types when needed:

stringValue = "123"
numValue = convert stringValue to number  // or number(stringValue)
stringFromNum = convert age to string     // or string(age)

Input and Output

Reading user input:

input userInput

Prompting for input:

output "Please enter your name: "
input userName

Displaying output:

output "Hello, " userName "!"

Constants

Define values that cannot be changed:

constant PI = 3.14159
constant MAX_USERS = 100

Basic Operators

Arithmetic Operators

sum = 1 + 1        // Addition
diff = 10 - 5      // Subtraction
product = 3 * 4    // Multiplication
quotient = 10 / 2  // Division
power = 2 ^ 3      // Exponentiation (also ** or "to the power of")
remainder = 10 % 3 // Modulus (also "modulus" or "remainder after")

String Concatenation

greeting = "Hello" " " "World"  // Results in "Hello World"
num = 10
message = "The number is {num}" // Results in "The number is 10"

Compound Assignments

num = 5
num++          // Same as num = num + 1
num *= 3       // Same as num = num * 3
num ^= 2       // Same as num = num ^ 2

What’s Next?

Now that you understand the basics, explore these topics:

• Comments and Formatting - Detailed comment syntax
• Data Types - In-depth look at all data types
• Operators - Complete operator reference
• Control Flow - if/else statements and more
• Loops - Iteration and repetition