Learn Smalltalk - 10 Code Examples & CST Typing Practice Test

Smalltalk is a dynamically typed, object-oriented programming language known for its pure object model, live environment, and influential role in the development of modern OOP concepts. Everything in Smalltalk is an object, including numbers, classes, and code blocks.

View all 10 Smalltalk code examples →

Smalltalk Counter and Theme Toggle Smalltalk Simple Addition Smalltalk Factorial Smalltalk Fibonacci Sequence Smalltalk Max of Two Numbers Smalltalk Array Sum Smalltalk Even Numbers Filter Smalltalk Conditional Counter Increment Smalltalk Resettable Counter Smalltalk Theme Toggle Only

Learn SMALLTALK with Real Code Examples

Updated Nov 20, 2025

Introduction & Fundamentals Setup & Configuration Architecture & Deep Internals Performance & Security Development Workflow Learning & Career Growth Business & Strategy Examples

Code Sample Descriptions

Smalltalk Counter and Theme Toggle

Object subclass: Counter [
    | count isDark |

    Counter class >> new [ ^ super new initialize ]

    initialize [
        count := 0.
        isDark := false.
        self updateUI.
    ]

    updateUI [
        Transcript show: 'Counter: ', count printString; cr.
        Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.
    ]

    increment [ count := count + 1. self updateUI ]
    decrement [ count := count - 1. self updateUI ]
    reset [ count := 0. self updateUI ]
    toggleTheme [ isDark := isDark not. self updateUI ]
]

| counter |
counter := Counter new.
counter increment.
counter increment.
counter toggleTheme.
counter decrement.
counter reset.

Demonstrates a simple counter with theme toggling using Smalltalk objects and messages.

Let’s Try →

Smalltalk Simple Addition

a := 10.
b := 20.
sum := a + b.
Transcript show: 'Sum: ', sum printString; cr.

Adds two numbers and prints the result.

Let’s Try →

Smalltalk Factorial

factorial := [:n | n <= 1 ifTrue: [1] ifFalse: [n * (factorial value: n-1)]].
Transcript show: 'Factorial 5: ', (factorial value: 5) printString; cr.

Calculates factorial recursively.

Let’s Try →

Smalltalk Fibonacci Sequence

fib := [:n | n < 2 ifTrue: [n] ifFalse: [(fib value: n-1) + (fib value: n-2)]].
1 to: 10 do: [:i | Transcript show: (fib value: i); cr].

Generates first 10 Fibonacci numbers.

Let’s Try →

Smalltalk Max of Two Numbers

a := 10.
b := 20.
max := a > b ifTrue: [a] ifFalse: [b].
Transcript show: 'Max: ', max printString; cr.

Finds the maximum of two numbers.

Let’s Try →

Smalltalk Array Sum

arr := #(1 2 3 4 5).
sum := 0.
arr do: [:x | sum := sum + x].
Transcript show: 'Sum: ', sum printString; cr.

Sums elements of an array.

Let’s Try →

Smalltalk Even Numbers Filter

arr := #(1 2 3 4 5).
arr do: [:x | (x \ 2 = 0) ifTrue: [Transcript show: x printString; cr]].

Prints even numbers from an array.

Let’s Try →

Smalltalk Conditional Counter Increment

count := 3.
(count < 5) ifTrue: [count := count + 1].
Transcript show: 'Count: ', count printString; cr.

Increment counter only if less than 5.

Let’s Try →

Smalltalk Resettable Counter

count := 0.
count := count + 1.
count := count + 1.
Transcript show: 'Count: ', count printString; cr.
count := 0.
Transcript show: 'Count: ', count printString; cr.

Counter that increments and can be reset.

Let’s Try →

Smalltalk Theme Toggle Only

isDark := false.
Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.
isDark := isDark not.
Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.
isDark := isDark not.
Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.

Toggles theme multiple times.

Let’s Try →

Frequently Asked Questions about Smalltalk

What is Smalltalk?

What are the primary use cases for Smalltalk?

Educational programming for OOP concepts. Rapid prototyping of applications. GUI-based application development. Dynamic systems with runtime object inspection. Research in programming languages and software design. Domain-specific languages and frameworks

What are the strengths of Smalltalk?

Highly flexible and dynamic. Excellent for learning OOP. Immediate feedback via live environment. Powerful reflective capabilities. Concise syntax and consistent object model

What are the limitations of Smalltalk?

Slower runtime compared to compiled languages. Less popular in modern mainstream development. Limited ecosystem and libraries. Image-based development can be challenging for team version control. Dynamic typing may lead to runtime errors

How can I practice Smalltalk typing speed?

CodeSpeedTest offers 10+ real Smalltalk code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

Learn Other Programming Languages

C React Python C++Rust TypeScript Kotlin PHP Java C#Ruby Mql Cql N1ql Cypher Gremlin Partiql Haskell Elixir Fsharp View all languages →

Code Sample Descriptions

Smalltalk Counter and Theme Toggle

Object subclass: Counter [
    | count isDark |

    Counter class >> new [ ^ super new initialize ]

    initialize [
        count := 0.
        isDark := false.
        self updateUI.
    ]

    updateUI [
        Transcript show: 'Counter: ', count printString; cr.
        Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.
    ]

    increment [ count := count + 1. self updateUI ]
    decrement [ count := count - 1. self updateUI ]
    reset [ count := 0. self updateUI ]
    toggleTheme [ isDark := isDark not. self updateUI ]
]

| counter |
counter := Counter new.
counter increment.
counter increment.
counter toggleTheme.
counter decrement.
counter reset.

Demonstrates a simple counter with theme toggling using Smalltalk objects and messages.

Let’s Try →

Smalltalk Simple Addition

a := 10.
b := 20.
sum := a + b.
Transcript show: 'Sum: ', sum printString; cr.

Adds two numbers and prints the result.

Let’s Try →

Smalltalk Factorial

factorial := [:n | n <= 1 ifTrue: [1] ifFalse: [n * (factorial value: n-1)]].
Transcript show: 'Factorial 5: ', (factorial value: 5) printString; cr.

Calculates factorial recursively.

Let’s Try →

Smalltalk Fibonacci Sequence

fib := [:n | n < 2 ifTrue: [n] ifFalse: [(fib value: n-1) + (fib value: n-2)]].
1 to: 10 do: [:i | Transcript show: (fib value: i); cr].

Generates first 10 Fibonacci numbers.

Let’s Try →

Smalltalk Max of Two Numbers

a := 10.
b := 20.
max := a > b ifTrue: [a] ifFalse: [b].
Transcript show: 'Max: ', max printString; cr.

Finds the maximum of two numbers.

Let’s Try →

Smalltalk Array Sum

arr := #(1 2 3 4 5).
sum := 0.
arr do: [:x | sum := sum + x].
Transcript show: 'Sum: ', sum printString; cr.

Sums elements of an array.

Let’s Try →

Smalltalk Even Numbers Filter

arr := #(1 2 3 4 5).
arr do: [:x | (x \ 2 = 0) ifTrue: [Transcript show: x printString; cr]].

Prints even numbers from an array.

Let’s Try →

Smalltalk Conditional Counter Increment

count := 3.
(count < 5) ifTrue: [count := count + 1].
Transcript show: 'Count: ', count printString; cr.

Increment counter only if less than 5.

Let’s Try →

Smalltalk Resettable Counter

count := 0.
count := count + 1.
count := count + 1.
Transcript show: 'Count: ', count printString; cr.
count := 0.
Transcript show: 'Count: ', count printString; cr.

Counter that increments and can be reset.

Let’s Try →

Smalltalk Theme Toggle Only

isDark := false.
Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.
isDark := isDark not.
Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.
isDark := isDark not.
Transcript show: 'Theme: ', (isDark ifTrue: ['Dark'] ifFalse: ['Light']); cr.

Toggles theme multiple times.

Let’s Try →

Frequently Asked Questions about Smalltalk

What is Smalltalk?

What are the primary use cases for Smalltalk?

What are the strengths of Smalltalk?

Highly flexible and dynamic. Excellent for learning OOP. Immediate feedback via live environment. Powerful reflective capabilities. Concise syntax and consistent object model

What are the limitations of Smalltalk?

How can I practice Smalltalk typing speed?

CodeSpeedTest offers 10+ real Smalltalk code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.