package StringTest; 
 
class A{ 
  int a=1; 
  char b='A'; 
  public A(){} 
  public A(int _a,char _b){ 
    this.a=_a; 
    this.b=_b; 
  } 
  public String toString(){ 
    return "a="+this.a+",b="+this.b; 
  } 
} 
 
 
public class ReferenceTest { 
  public static A changeA(A classa){ 
    classa.a=2; 
    classa.b='B'; 
    return classa; 
  } 
   
  public static String changeString(String str){ 
     System.out.println(str.hashCode()); 
     str=str.toLowerCase(); 
     System.out.println(str.hashCode()); 
     return str; 
  } 
   
  public static int changeint(int a){ 
    a=a+1; 
    return a; 
  } 
   
  public static Integer changeInteger(Integer a){ 
    a=new Integer(9); 
    return a; 
  } 
   
  public static int[] changeintarray(int a[]){ 
    a[0]=10; 
    return a; 
  } 
   
  public static void printArray(int a[]){ 
    for(int i=0;i<a.length;i++){ 
      System.out.print(a[i]+" "); 
    } 
    System.out.println(); 
  } 
   
  public static void main(String[] args) { 
    //自定義的對象傳遞的是引用 
    A a=new A(); 
    A b=changeA(a); 
    System.out.println(a); 
    System.out.println(b);  
    System.out.println("----------------------"); 
    //String對象作為參數(shù)傳遞的也是引用(只是String對象的值不能變,每一個修改String對象的值都會重新創(chuàng)建一個新的String對象用以保存修改后的值，原來的值不會變) 
    String str1="HUHUALIANG"; 
    System.out.println(str1.hashCode()); 
    String str2=changeString(str1); 
    System.out.println(str2.hashCode()); 
    System.out.println(str1); 
    System.out.println(str2);  
    System.out.println("----------------------"); 
    //基本類型是值傳遞 
    int inta=8; 
    int intb=changeint(inta); 
    System.out.println(inta); 
    System.out.println(intb);  
    System.out.println("----------------------"); 
    //基本類型的包裝集作為參數(shù)傳遞的是值而不是引用 
    Integer c=new Integer(1); 
    Integer d=changeInteger(c); 
    System.out.println(c); 
    System.out.println(d);  
    System.out.println("----------------------"); 
    //數(shù)組傳遞的是引用 
    int [] arraya={0,1,2,3}; 
    int [] arrayb=changeintarray(arraya); 
    printArray(arraya); 
    printArray(arrayb); 
  } 
}