Learn Bcpl - 10 Code Examples & CST Typing Practice Test

BCPL (Basic Combined Programming Language) is a minimalist, typeless systems programming language designed for writing compilers, operating systems, and early software infrastructure.

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BCPL Counter and Theme Toggle BCPL Random Number Generator BCPL Todo List BCPL Dice Roller BCPL Countdown Timer BCPL Prime Checker BCPL Temperature Converter BCPL Shopping Cart BCPL Name Greeting BCPL Stopwatch

Learn BCPL with Real Code Examples

Updated Nov 21, 2025

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Code Sample Descriptions

BCPL Counter and Theme Toggle

LET count=0
LET isDark=0

FUN updateUI() =
    WRITEF("Counter: %N\n", count)
    IF isDark THEN
        WRITEF("Theme: Dark\n")
    ELSE
        WRITEF("Theme: Light\n")
    ENDIF

FUN increment() =
    count = count + 1
    updateUI()

FUN decrement() =
    count = count - 1
    updateUI()

FUN reset() =
    count = 0
    updateUI()

FUN toggleTheme() =
    isDark = 1 - isDark
    updateUI()

# Simulate actions
updateUI()
increment()
increment()
toggleTheme()
decrement()
reset()

Demonstrates a simple counter with theme toggling using BCPL variables and functions.

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BCPL Random Number Generator

LET i=0
FOR i=1 TO 3 DO
    LET num = RAND() MOD 100 + 1
    WRITEF("Random %N: %N\n", i, num)
OD

Generates random numbers between 1 and 100 and prints them.

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BCPL Todo List

LET todos = []
FUN addTask(task) =
    APPEND(todos, task)
    WRITEF("Todos: %S\n", todos)

FUN removeTask(index) =
    DELETE(todos, index)
    WRITEF("Todos: %S\n", todos)

# Simulate actions
addTask("Buy milk")
addTask("Write BCPL code")
removeTask(1)

Maintains a simple todo list with add and remove functionality.

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BCPL Dice Roller

LET i=0
FOR i=1 TO 3 DO
    LET roll = RAND() MOD 6 + 1
    WRITEF("Roll %N: %N\n", i, roll)
OD

Rolls a six-sided dice three times.

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BCPL Countdown Timer

LET count = 5
WHILE count >= 0 DO
    WRITEF("Countdown: %N\n", count)
    count = count - 1
OD
WRITEF("Done!\n")

Counts down from 5 to 0.

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BCPL Prime Checker

LET nums = [7,10,13]
LET n=0
FOR n IN nums DO
    LET isPrime = 1
    LET i=2
    WHILE i<n DO
        IF n MOD i = 0 THEN isPrime = 0 END
        i = i + 1
    OD
    IF isPrime THEN WRITEF("%N is Prime\n", n) ELSE WRITEF("%N is Not Prime\n", n) END
OD

Checks if numbers are prime.

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BCPL Temperature Converter

FUN cToF(c) = c*9/5+32
FUN fToC(f) = (f-32)*5/9
WRITEF("25°C = %N°F\n", cToF(25))
WRITEF("77°F = %N°C\n", fToC(77))

Converts Celsius to Fahrenheit and Fahrenheit to Celsius.

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BCPL Shopping Cart

LET cart = []
LET prices = []
FUN addItem(item, price) = APPEND(cart, item); APPEND(prices, price)
FUN removeItem(index) = DELETE(cart,index); DELETE(prices,index)
# Simulate actions
addItem("Apple",2)
addItem("Banana",3)
removeItem(1)

Adds and removes items in a shopping cart with total cost.

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BCPL Name Greeting

FUN greet(name) = WRITEF("Hello, %S! Welcome!\n", name)
# Simulate greetings
greet("Saurav")
greet("Alice")
greet("Bob")

Greets users by name.

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BCPL Stopwatch

LET time = 0
WHILE time < 5 DO
    WRITEF("Stopwatch: %N seconds\n", time)
    time = time + 1
OD
WRITEF("Done!\n")

Simulates a stopwatch incrementing seconds.

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Frequently Asked Questions about Bcpl

What is Bcpl?

BCPL (Basic Combined Programming Language) is a minimalist, typeless systems programming language designed for writing compilers, operating systems, and early software infrastructure.

What are the primary use cases for Bcpl?

Compiler and interpreter development. Operating system prototyping. Low-level systems programming. Teaching early programming language design. Legacy software and historical research

What are the strengths of Bcpl?

Extremely lightweight and simple. Highly portable across machines. Influential in the development of C and other languages. Excellent for low-level, systems-focused programming. Minimalist design facilitates compiler construction

What are the limitations of Bcpl?

No type safety, relies on programmer discipline. Not suitable for large-scale modern software. Limited libraries and tooling. No native GUI or modern OS support. Mostly of historical or educational interest today

How can I practice Bcpl typing speed?

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

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Code Sample Descriptions

BCPL Counter and Theme Toggle

LET count=0
LET isDark=0

FUN updateUI() =
    WRITEF("Counter: %N\n", count)
    IF isDark THEN
        WRITEF("Theme: Dark\n")
    ELSE
        WRITEF("Theme: Light\n")
    ENDIF

FUN increment() =
    count = count + 1
    updateUI()

FUN decrement() =
    count = count - 1
    updateUI()

FUN reset() =
    count = 0
    updateUI()

FUN toggleTheme() =
    isDark = 1 - isDark
    updateUI()

# Simulate actions
updateUI()
increment()
increment()
toggleTheme()
decrement()
reset()

Demonstrates a simple counter with theme toggling using BCPL variables and functions.

Let’s Try →

BCPL Random Number Generator

LET i=0
FOR i=1 TO 3 DO
    LET num = RAND() MOD 100 + 1
    WRITEF("Random %N: %N\n", i, num)
OD

Generates random numbers between 1 and 100 and prints them.

Let’s Try →

BCPL Todo List

LET todos = []
FUN addTask(task) =
    APPEND(todos, task)
    WRITEF("Todos: %S\n", todos)

FUN removeTask(index) =
    DELETE(todos, index)
    WRITEF("Todos: %S\n", todos)

# Simulate actions
addTask("Buy milk")
addTask("Write BCPL code")
removeTask(1)

Maintains a simple todo list with add and remove functionality.

Let’s Try →

BCPL Dice Roller

LET i=0
FOR i=1 TO 3 DO
    LET roll = RAND() MOD 6 + 1
    WRITEF("Roll %N: %N\n", i, roll)
OD

Rolls a six-sided dice three times.

Let’s Try →

BCPL Countdown Timer

LET count = 5
WHILE count >= 0 DO
    WRITEF("Countdown: %N\n", count)
    count = count - 1
OD
WRITEF("Done!\n")

Counts down from 5 to 0.

Let’s Try →

BCPL Prime Checker

LET nums = [7,10,13]
LET n=0
FOR n IN nums DO
    LET isPrime = 1
    LET i=2
    WHILE i<n DO
        IF n MOD i = 0 THEN isPrime = 0 END
        i = i + 1
    OD
    IF isPrime THEN WRITEF("%N is Prime\n", n) ELSE WRITEF("%N is Not Prime\n", n) END
OD

Checks if numbers are prime.

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BCPL Temperature Converter

FUN cToF(c) = c*9/5+32
FUN fToC(f) = (f-32)*5/9
WRITEF("25°C = %N°F\n", cToF(25))
WRITEF("77°F = %N°C\n", fToC(77))

Converts Celsius to Fahrenheit and Fahrenheit to Celsius.

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BCPL Shopping Cart

LET cart = []
LET prices = []
FUN addItem(item, price) = APPEND(cart, item); APPEND(prices, price)
FUN removeItem(index) = DELETE(cart,index); DELETE(prices,index)
# Simulate actions
addItem("Apple",2)
addItem("Banana",3)
removeItem(1)

Adds and removes items in a shopping cart with total cost.

Let’s Try →

BCPL Name Greeting

FUN greet(name) = WRITEF("Hello, %S! Welcome!\n", name)
# Simulate greetings
greet("Saurav")
greet("Alice")
greet("Bob")

Greets users by name.

Let’s Try →

BCPL Stopwatch

LET time = 0
WHILE time < 5 DO
    WRITEF("Stopwatch: %N seconds\n", time)
    time = time + 1
OD
WRITEF("Done!\n")

Simulates a stopwatch incrementing seconds.

Let’s Try →

Frequently Asked Questions about Bcpl

What is Bcpl?

BCPL (Basic Combined Programming Language) is a minimalist, typeless systems programming language designed for writing compilers, operating systems, and early software infrastructure.

What are the primary use cases for Bcpl?

Compiler and interpreter development. Operating system prototyping. Low-level systems programming. Teaching early programming language design. Legacy software and historical research

What are the strengths of Bcpl?

What are the limitations of Bcpl?

How can I practice Bcpl typing speed?

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