条件控制

if 语句

// if 判断
var number = 1;
var isMax = true;
if (number > 0) {
  isMax = true;
} else {
  isMax = false;
}

for 语句

// for 循环
var list = [0, "val1", "val2", true, false];
for (var index = 0; index < list.length; index++) {
  print(list[index]);
}
for (var item in list) {
  print(item);
}

while 语句

// while 循环
var index = 0;
while (index < 5) {
  index++;
  print(index);
}
do {
  index--;
  print(index);
} while (index > 0);

break 和 continue

// break 和 continue
var list2 = [0, "val1", "val2", true, false];
for (var index = 0; index < list2.length; index++) {
  if (index == 1) {
    // 跳出当前循环体
    break;
  }
  print(list[index]);
}
for (var index = 0; index < list2.length; index++) {
  if (index == 1) {
    // 跳出本次循环条件，继续执行其余循环
    continue;
  }
  print(list[index]);
}

switch case 语句

// switch case 语句
// 比较类型：num，String，编译器常量，对象，枚举
var name = "Dart";
switch (name) {
  case "Dart":
    print("It is Dart");
    break;
  case "Java":
    print("It is Java");
    break;
  default:
    print("It is None");
    break;
}

// 使用 continue 跳转标签
switch (name) {
  Test1: // 给分支添加标签
  case "Dart":
    print("It is Dart");
    // 跳转到指定标签；会执行标签的分支
    continue Test3;
  Test2:
  case "Java":
    print("It is Java");
    break;
  Test3:
  default:
    print("It is None");
    break;
}