Question

How to use typedef as a pointer to function in Dart

Answer 1

typedef Ref(int a , int b); 

Add(int a,int b) { 
   print("Add = ${a + b}"); 
} 

Subtract(int a,int b) { 
   print("Subtract = ${a - b}"); 
}

Divide(int a,int b) { 
   print("Divide = ${a / b}"); 
}  

void main() { 
   Ref ptr = Add; 
   ptr(4, 8); 
   
   ptr = Subtract; 
   ptr(9, 2); 
   
   ptr = Divide; 
   ptr(18, 6); 
} 





/*
run:

Add = 12
Subtract = 7
Divide = 3.0

*/

 

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Answer 2

typedef Ref(int a , int b); 

Add(int a,int b) { 
   print("Add = ${a + b}"); 
} 

Subtract(int a,int b) { 
   print("Subtract = ${a - b}"); 
}

Divide(int a,int b) { 
   print("Divide = ${a / b}"); 
}  

Calc(int a, int b ,Ref ptr){ 
   ptr(a, b); 
}  

void main() { 
    Calc(4, 8, Add); 
    Calc(9, 2, Subtract); 
    Calc(18, 6, Divide); 
} 





/*
run:

Add = 12
Subtract = 7
Divide = 3.0

*/

 

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