Summary of method parameters in Java

JavaProgramThe design language uses value calls. That is to say, the method obtains a copy of all parameter values. In particular, the method cannot be modified to any basic data class passed to it.

There are two types of method parameters:
1. Basic data types (numbers and boolean values ).
2. Object reference.

A method cannot modify a parameter of the basic data type. The object reference as a parameter is different. The object state referenced by the object parameter can be changed because the Method

What we get is the copy of the object reference. The object reference and its copy reference the same object at the same time.

The Java programming language does not use reference calls for objects. In fact, object references are passed through values.

Summarize the usage of method parameters in the Java programming language:
1. A method cannot modify a parameter of the basic data type (that is, an open value or a Boolean value ).
2. A method can change the state of an object parameter.
3. A method object parameter references a new object without changing the value of the object outside the method.

 

 1   Package Com. Action;  2   3   Public   Class  Test {  4   5       Private   Static   Int I = 1 ;  6       Private   Static String S = "string1" ;  7      Private   Static String [] Ss = {"11", "BB", "cc" };  8       Private   Static   Int J = 10 ;  9   10       Public   Int  II;  11       Static  { 12 System. Out. println ("static Block 1" );  13   System. Out. println (I );  14   }  15       Static  {  16   17 System. Out. println ("static Block 2" );  18   }  19   20      /**  21   *  @ Param  ARGs  22        */  23       Public   Static   Void  Main (string [] ARGs ){  24           25 Test T = New  Test ();  26  T. changeint (I );  27 System. Out. println ("Incoming int value:" + I + ":" + J );  28   29   T. changestring (s );  30 System. Out. println ("Incoming string value 1:" + S );  31   32   T. changestring2 (s );  33 System. Out. println ("Incoming string value 2:" + S );  34  35   T. changestrings (SS );  36 System. Out. println ("Incoming array:" + SS [0 ]);  37   38   T. changetest (t );  39 System. Out. println ("Incoming object" + T. I );  40   41 T. II = 111 ;  42   T. changetest1 (t ); 43   System. Out. println (T. II );  44   }  45   46       Public   Void Changeint ( Int  I ){  47 I = 10 ;  48 J ++ ;  49   } 50   51       Public   Void  Changestring (string s ){  52 S = New String ("changestring" );  53   }  54   55       Public   Void  Changestring2 (string s ){  56 S. Replace ("O", "" );  57   }  58   59       Public   Void  Changestrings (string [] S ){  60 S [0] = "numberchange" ;  61   }  62   63       Public   Void Changetest (test T ){  64 Test TT = New  Test ();  65 Tt. I = 100 ;  66 T = TT;  67   68   }  69   70       Public   Void  Changetest1 (test T ){ 71 Test TT = New  Test ();  72 TT. II = 1 ;  73 T = TT;  74   }  75   76 }

 

Result:

Static Block 1
1
Static Block 2
Int value: 1: 11
String Value 1: string1
String Value 2: string1
Into array: numberchange
Round object 100
111

A method can contain multiple static blocks.