JVM中的常见约定

The JVM uses a compact way of storing method signatures, of which constructors are considered a special case.

For your example:

() indicates a method taking no arguments
V indicates that it returns nothing
The other parts of the scheme are:

B - byte
C - char
D - double
F - float
I - int
J - long
S - short
V - void
Z - boolean
[ - array of the thing following the bracket
L [class name] ; - instance of this class, with dots becoming slashes
( [args] ) [return type] - method signature
For example:

public int foo(String bar, long[][] baz)
would become

(Ljava/lang/String;[[J)I
See the spec at Sun^H^H^HOracle's web site

#include<stdio.h>

union var{        
    long int l;        
    int i;
};

main(){        
    union var v;        
    v.l = 5;        
    printf("v.l is %d\n",v.i);        
    v.i = 6;        
    printf("now v.l is %ld! the address is %p\n",v.l,&v.l);        
    printf("now v.i is %d! the address is %p\n",v.i,&v.;
}

结果：v.l is 5now v.l is 6! the address is 0xbfad1e2c