Learn REBOL-RED with Real Code Examples

count: 0
isDark: false

updateUI: func [] [
    print rejoin ["Counter: " count]
    print rejoin ["Theme: " either isDark ["Dark"] ["Light"]]
]

increment: func [] [
    count: count + 1
    updateUI/()
]

decrement: func [] [
    count: count - 1
    updateUI/()
]

reset: func [] [
    count: 0
    updateUI/()
]

toggleTheme: func [] [
    isDark: not isDark
    updateUI/()
]

; Simulate actions
updateUI/()
increment/()
increment/()
toggleTheme/()
decrement/()
reset/()

Demonstrates a simple counter with theme toggling using REBOL/Red variables and functions.

foreach i [1 2 3] [
    num: random 100 + 1
    print rejoin ["Random " i ": " num]
]

Generates random numbers between 1 and 100 and prints them.

todos: copy []

addTask: func [task] [
    append todos task
    print todos
]

removeTask: func [index] [
    remove todos index
    print todos
]

; Simulate actions
addTask "Buy milk"
addTask "Write REBOL code"
removeTask 1

Maintains a simple todo list with add and remove functionality.

foreach i [1 2 3] [
    roll: random 6 + 1
    print rejoin ["Roll " i ": " roll]
]

Rolls a six-sided dice three times.

count: 5
while [count >= 0] [
    print rejoin ["Countdown: " count]
    count: count - 1
]
print "Done!"

Counts down from 5 to 0.

isPrime: func [n] [
    if n < 2 [return false]
    foreach i 2 n-1 [
        if n // i = 0 [return false]
    ]
    return true
]

nums: [7 10 13]
foreach n nums [
    print rejoin [n " is " either isPrime n ["Prime"] ["Not Prime"]]
]

Checks if numbers are prime.

cToF: func [c] [c * 9 / 5 + 32]
fToC: func [f] [(f - 32) * 5 / 9]
print rejoin ["25°C = " cToF 25 ":F"]
print rejoin ["77°F = " fToC 77 ":C"]

Converts Celsius to Fahrenheit and Fahrenheit to Celsius.

cart: copy []
prices: copy []

addItem: func [item price] [
    append cart item
    append prices price
    print rejoin ["Cart: " cart]
    print rejoin ["Total: " sum prices]
]

removeItem: func [index] [
    remove cart index
    remove prices index
    print rejoin ["Cart: " cart]
    print rejoin ["Total: " sum prices]
]

; Simulate actions
addItem "Apple" 2
addItem "Banana" 3
removeItem 1

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

greet: func [name] [print rejoin ["Hello, " name "! Welcome!"]]

greet "Saurav"
greet "Alice"
greet "Bob"

Greets users by name.

time: 0
while [time < 5] [
    print rejoin ["Stopwatch: " time " seconds"]
    time: time + 1
]
print "Done!"

Simulates a stopwatch incrementing seconds.