Java convention for class field definition in constructor? -

the question: difference these 2 styles have? 1 preferred on other, why?

if have field variables define parameters of constructor, in c++ :

public class thingamajing{      private int var1, var2;      public thingamajing(int var1_ , int var2_ ){        var1 = var1_;         var2 = var2_;      } } 

but in lot of java examples online, find style:

public class thingamajing{      private int var1, var2;      public thingamajing(int var1 , int var2 ){        this.var1 = var1;         this.var2 = var2;      } }