[flutter]#조건문과 제어문

예제3-6 조건문과 제어문

 

void main(){
  //1.if문
  int even = 78;
  int odd = 99;
  if (even % 2 ==0){
    print('$even is even number');
  }
  if  (odd % 2 ==0){
    print('$odd is not even number');
  }else{
    print('$odd is odd number');
  }
  //if문은 조건문의 대표. 안에 있는 표현식의 참과 거짓을 구별한다. int 형인 even변수에는 짝수가 들어있고

  //2. for문
  List<String> fruits = ['apple', 'banana', "kiwi"];
  for (String fruit in fruits){
    print('I like $fruit');
  }

  //3.while문
  List<num> numbers = [100, 200, -1];
  int i=0;
  while(numbers[i] > 0){
    print('${numbers[i]} is positive');
    i = i +1;
  }

  //4.do-while문
  int j =5;
  do {
    print(j);
    j--;
  }while(j>0);

  //5.switch/ case문
  List<num> httpCodes = [200, 401, 500];
  for (num http in httpCodes){
    switch (http) {
      case 200:
        print('200 is OK');
        break;
      case 401:
        print('401 is Unautherized');
        break;
      case 500:
        print('500 is Server Error');
        break;
    }
  }
}

The type 'num' is not exhaustively matched by the switch cases since it doesn't match 'double()'.

 

The type 'num' is not exhaustively matched by the switch cases since it doesn't match 'double()'.

num을 double로 바꾸어보아야겠다

// 다트에는 c와 자바에서 제공하는 기본적인 조건문과 제어문을 제공한다.

void main(){
  //1.if문
  int even = 78;
  int odd = 99;
  if (even % 2 ==0){
    print('$even is even number');
  }
  if  (odd % 2 ==0){
    print('$odd is not even number');
  }else{
    print('$odd is odd number');
  }

  //2. for문
  List<String> fruits = ['apple', 'banana', "kiwi"];
  for (String fruit in fruits){
    print('I like $fruit');
  }

  //3.while문
  List<num> numbers = [100, 200, -1];
  int i=0;
  while(numbers[i] > 0){
    print('${numbers[i]} is positive');
    i = i +1;
  }

  //4.do-while문
  int j =5;
  do {
    print(j);
    j--;
  }while(j>0);

  //5.switch/ case문
  List<double> httpCodes = [200, 401, 500];
  for (double http in httpCodes){
    switch (http) {
      case 200:
        print('200 is OK');
        break;
      case 401:
        print('401 is Unautherized');
        break;
      case 500:
        print('500 is Server Error');
        break;
    }
  }
}

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