Input and Output

Communication with users is essential in any program. Common Pseudocode provides simple statements for reading input and displaying output.

Output Statement

Display information to the user with the output statement:

output "Hello, World!"

Outputting Variables

Display variable values:

name = "Alice"
age = 30
output name
output age

Concatenating Output

Combine text and variables:

name = "Bob"
age = 25
output "Hello, my name is " name " and I am " age " years old"

String Interpolation

Embed variables directly in strings using curly braces:

name = "Charlie"
score = 95
output "Player {name} scored {score} points!"

Multiple Output Statements

output "Welcome to the program!"
output ""  // Empty line
output "Please select an option:"
output "1. Start"
output "2. Exit"

Input Statement

Read user input with the input statement:

input userInput

The value entered by the user is stored in the variable userInput.

Prompting for Input

It’s good practice to tell users what to enter:

output "What is your name? "
input userName

output "How old are you? "
input age

Single Line Prompt and Input

output "Enter your email: "
input userEmail

Complete Example

Here’s a full program that uses input and output:

// Greeting program
output "=== Welcome ==="
output ""
output "What is your name? "
input userName
output "What is your age? "
input userAge

output ""
output "Hello, {userName}!"
output "You are {userAge} years old."

// Calculate birth year (approximate)
currentYear = 2024
birthYear = currentYear - userAge
output "You were born around {birthYear}."

Menu Example

Creating an interactive menu:

output "Options: "
output "1. Book a ticket"
output "2. Cancel a ticket"
output "3. View a ticket"
output "4. View all tickets"
output "5. Track train"
output "6. Track all trains"
output "9. Exit"
output ""
output "Please enter an option: "
input userOption

Tips

• Always provide clear prompts so users know what to enter
• Use empty output statements (output "") to create blank lines for readability
• When reading numbers, remember to convert string input to number if needed
• Consider validating user input to handle errors gracefully

output "Enter a number: "
input userInput
number = convert userInput to number

if is number(number)
    output "You entered: {number}"
else
    output "That's not a valid number!"