Constructor overload, the method

Construction method

The name of the constructor of the class with the same name

No return value can not write void

 

If you do not write constructor, the default constructor without parameter to generate a

If there is to write a reference or a constructor with no arguments, it will not generate a default constructor with no arguments

 

. 1  class A {
 2      public  int I; // I herein is not in vivo, are members of the variables (attributes),
 3                      // can not initialize, defaults to numeric type 0 
. 4      public  boolean In Flag;   // if boolean type, default to false 
. 5      
. 6      public  void Show () {
 . 7          System.out.printf ( "% D", i);   // this case, although there is no assignment to the i, but the output will be 0 
. 8          System.out.printf ( "% B ", In Flag); // Boolean type output B% b or% 
. 9      }
 10  }
 . 11  
12 is  class  const {
 13 is      public  static void main (String [] args) {
 14          A AA = new new A ();
 15          aa.show (); // call to show method, outputs 0 
16          
. 17          int K; // here K is in vivo, belongs local variables, initialization is not being given
 18 is              // Java requires all local variables must be initialized before use 
. 19          System.out.printf ( "% D", K); // compiler given 
20      }
 21 }

 

Overloaded methods

The method of the same name parameter to do similar things in different shape, which is called method overloading

Method overloading Requirements:

1. Method shape parameter number
2. Parameter sequential method
3. Method according to the type of shape parameter

At least one of these three is not the same

 

If the two methods just return value method (return value type) are not the same, other are the same, which constitute overloaded methods, because they can not determine which method to call the method call, it will be a compile-time error!