Dart之运算符(算数、关系、逻辑、赋值、条件)

main(){
//  算数运算符
int a=6;
int b=4;
//加法 10
print(a+b);
//减法 2
print(a-b);
//乘法 24
print(a*b);
//除法 1.5
print(a/b);
//整除 1
print(a~/b);
//取余 2
print(a%b);
}

main() {
//  关系运算符
  int a = 6;
  int b = 4;
//  等于 false
  print(a == b);
//不等于 true
  print(a != b);
//大于 true
  print(a > b);
//小于 false
  print(a < b);
//大于等于 true
  print(a >= b);
//小于等于 false
  print(a <= b);
}

main() {
  bool flag1 = true;
  bool flag2 = false;
 
  print(flag1);
//true
  print(flag2);
//false
  print("-------");
  print(!flag1);
//false
  print(!flag2);
//true
  print("-------");
  print(flag1 || flag2);
//true
  print(flag2 || flag1);
//true
  print(flag1 && flag2);
//false
  print(flag2 && flag1);
//false
}

main() {
//1、基本赋值运算
  int a = 10;
  print(a); //10
  int b = 10;
  b ??= 15;
  print(b); //10
  print("------------");
//  2、复合赋值运算
  var c = 12;
  c = c + 10;
  print(c); //22
  c += 10;
  print(c); //32
  int d = 2;
  d *= 2;
  print(d); //4
  double e = 3;
  e /= 2;
  print(e); //1.5
  int f = 7;
  f %= 5;
  print(f); //2
  int g = 9;
  g ~/= 4;
  print(g); //2
}

main() {
//1、if else switch case
  bool flag = true;
  if (flag) {
    print("true"); //true
  } else {
    print('false');
  }
  int num = 2;
  switch (num) {
    case 1:
      print(1);
      break;
    case 2:
      print(2); //2
      break;
    default:
      print("error");
      break;
  }
//2、三目运算符
 
var flag_1=true;
  var c=flag_1?"a":"b";
  print(c); //a
 
  //3、??运算
 
  var a;
  var b=a??10;
  print(b); //10
}