Repeating things - TorbScript

Computers are good at doing the same thing many times. A for loop runs the lines in its curly braces once for every number from a start to an end, and gives the number a name each time round.

1..=3 means the numbers from 1 up to and including 3. 1..3 stops before the 3.

for round in 1..=3 {
  print "Round {round}"
}
print "Done!"
// prints Round 1
// prints Round 2
// prints Round 3
// prints Done!

As long as#

A while loop asks a question before every round, and stops as soon as the answer is no. Something inside the loop has to change the answer, or the loop never ends.

var countdown = 3
while countdown > 0 {
  print countdown
  countdown = countdown - 1
}
print "Liftoff!"
// prints 3
// prints 2
// prints 1
// prints Liftoff!

Exercise#

Add up all numbers from 1 to 10 with a for loop, so the program prints 55.

var sum = 0
print sum

Expected output

Run it on your computer: torb run repeating-things.trb

Hint

Put a loop for number in 1..=10 { ... } between the two lines, and in it write sum = sum + number.

Solution

var sum = 0
for number in 1..=10 {
  sum = sum + number
}
print sum
// prints 55

Recap#

for number in 1..=10 repeats for every number of a range, and while repeats as long as its question is answered yes.