Notes on ‘Refactoring ‘ — 3.2 Replace Magic Number with Symbolic Constant

Before Refactoring

 validate1(){
   if(size < 2){
     addError(...); 
   }
 }

 validate2(){
   if(size < 2){
     addError(...); 
   }
 }

After Refactoring

 static final int MIN_SIZE = 2; 
 validate1(){
   if(size < MIN_SIZE){
     addError(...); 
   }
 }

 validate2(){
   if(size < MIN_SIZE){
     addError(...); 
   }
 }