You can repeat expressions in loops using the same keywords as in many languages. There are several kinds of loops in Dart:

• Standard for
• for-in
• while
• do while

for loops

If you need to know the index, your best bet is the standard for loop:

for (var i = 0; i < 5; i++) {
  print(i);
}
// prints
0
1
2
3
4

If you don't care about the index, the for-in loop is great option. It's easier to read and more concise to write.

List<String> pets = ['Nora', 'Wallace', 'Phoebe'];
for (var pet in pets) {
  print(pet);
}
// prints
'Nora'
'Wallace'
'Phoebe'

while loops

while loops behave as you'd expect. They evaluate the condition before the loop runs -- meaning it may never run at all:

while(someConditionIsTrue) {
  // do some things
}

do-while loops, on the other hand, evaluate the condition after the loop runs. So they always execute the code in the block at least once:

do {
  // do somethings at least once
} while(someConditionIsTrue);

break and continue

These two keywords help you manipulate the flow of the loop. Use continue in a loop to immediately jump to the next iteration, and use break to break out of the loop completely:

for (var i = 0; i < 55; i++) {
  if (i == 5) {
    continue; // jump to next iteration
  }
  if (i == 10) {
    break; // stop loop immediately
  }
  print(i);
}
// prints to the console
0
1
2
3
4
6
7
8
9