Dart语言Typedefs示例2

typedef ManyOperation(int firstNo , int secondNo);   //function signature 
Add(int firstNo,int second){ 
   print(Add result is ${firstNo+second}); 
}  
Subtract(int firstNo,int second){
   print(Subtract result is ${firstNo-second}); 
}  
Divide(int firstNo,int second){ 
   print(Divide result is ${firstNo/second}); 
}  
Calculator(int a,int b ,ManyOperation oper){ 
   print(Inside calculator); 
   oper(a,b); 
}  
main(){ 
   Calculator(5,5,Add); 
   Calculator(5,5,Subtract); 
   Calculator(5,5,Divide); 
}