Dart
Dart : Control flow statements
iosroid
2019. 9. 17. 17:05
Dart language tour 에서 예제 코드만 긁어서 모아 보았다.
// if else
if (isRaining()) {
you.bringRainCoat();
} else if (isSnowing()) {
you.wearJacket();
} else {
car.putTopDown();
}
// for loop
var message = StringBuffer('Dart is fun');
for (var i = 0; i < 5; i++) {
message.write('!');
}
// closure in for loop, forEach()
var callbacks = [];
for (var i = 0; i < 2; i++) {
callbacks.add(() => print(i));
}
callbacks.forEach((c) => c());
// for-in iterable classes
var collection = [0, 1, 2];
for (var x in collection) {
print(x); // 0 1 2
}
// while
while (!isDone()) {
doSomething();
}
// do-while
do {
printLine();
} while (!atEndOfPage());
// break and continue
while (true) {
if (shutDownRequested()) break;
processIncomingRequests();
}
for (int i = 0; i < candidates.length; i++) {
var candidate = candidates[i];
if (candidate.yearsExperience < 5) {
continue;
}
candidate.interview();
}
// using Iterable (where(), forEach())
candidates
.where((c) => c.yearsExperience >= 5)
.forEach((c) => c.interview());
// switch and case
var command = 'OPEN';
switch (command) {
/*
case 'OPEN':
executeOpen();
// ERROR: Missing break
*/
case 'CLOSED':
executeClosed();
break;
case 'OPEN':
executeOpen();
break;
default:
executeUnknown();
/*
case 'CLOSED': // Empty case falls through.
case 'NOW_CLOSED':
// Runs for both CLOSED and NOW_CLOSED.
executeNowClosed();
break;
*/
}
// continue and label
var command = 'CLOSED';
switch (command) {
case 'CLOSED':
executeClosed();
continue nowClosed;
// Continues executing at the nowClosed label.
nowClosed:
case 'NOW_CLOSED':
// Runs for both CLOSED and NOW_CLOSED.
executeNowClosed();
break;
}
// assert
assert(text != null);
assert(number < 100);
assert(urlString.startsWith('https'));
assert(urlString.startsWith('https'),
'URL ($urlString) should start with "https".');