For Loop

A loop runs the same block of code several times. Instead of writing the same print() five times, you write it once inside a loop.

The for loop runs its block once for every number in a range. range(start, end) gives the numbers from start up to end, not including end:

for i in range(0, 5):
	print(i)

0
1
2
3
4

Each run of the block is an iteration. On every iteration, the loop variable i holds the next number of the range. The for line ends with a colon, and the lines that repeat are indented one level deeper.

When the range starts at 0, you can leave the start out: range(5) gives the same numbers as range(0, 5).

Inside the block, i works like any other variable:

for i in range(1, 4):
	print("Item number: ", i)

Item number: 1
Item number: 2
Item number: 3

A loop can also build up a result. This program adds up all the numbers from 1 to 100 and prints 5050:

var total := 0
for i in range(1, 101):
	total += i
print(total)

The last print() is not indented under the for line, so it runs once, after the loop has finished.