What is a thread group? ,Java, C ,C++, ASP, ASP.net C# ,Struts ,Questions & Answer, Struts2, Ajax, Hibernate, Swing ,JSP , Servlet, J2EE ,Core Java ,Stping, VC++, HTML, DHTML, JAVASCRIPT, VB ,CSS, interview ,questions, and answers, for,experienced, and fresher
What is a thread group?

A thread group represents a set of threads. Every Java thread is a member of a thread group. In addition, a thread group can also include other thread groups. Threads can only access the ThreadGroup to which they belong. Thread groups provide a mechanism for collecting multiple threads into a single object and manipulating those threads all at once, rather than individually. A tree structure can be formed from ThreadsGroups containing other ThreadGroups. 
Java provides the ThreadGroup class for creating and managing the thread groups. The ThreadGroup class provides two constructors :

ThreadGroup(String name)
ThreadGroup(ThreadGroup parent, String name)

More interview questions and answers
What is diamond problem?
How many JVM's we can run in a system?
Why ArrayList is faster than Vector?
What is the security mechnaism used in java?
What is phantom memory?
What is reflection?
What are the differences between JIT and HotSpot?
How would you implement a thread pool?
What is the difference between throw and throws clause?
What is the difference between Comparable and Comparator ?
What is the difference between List, Set and Map?
What is the difference between Exception and Error ?
What is meant by Open Source ?
How do you send data from an applet to Servlet ? What are the steps involved in it ?
What are the different inner classes types?
What is Nested top-level classes?
What is Member classes?
Can a top level class be private or protected?
How will you invoke any external process in Java?
What is composition?
What is aggregation?
What are the methods in Object?
What is the relationship between synchronized and volatile keyword?
What factors are used to decide using synchronized or volatile?
What are the drawbacks of inheritance?
What are the restrictions placed on the values of each case of a switch statement?
If aaaa is an array then why aaaa.length why not aaaa.length()?
What is dynamic typing?
What is static typig?
What is HashMap and Map?
What is an Object and how do you allocate memory to it?
What is UNICODE?
What is a stream and what are the types of Streams and classes of the Streams?
What is the difference between TCP/IP and UDP?
What is Inter-Thread communication?.
What is a thread group?
Why is UTFDataFormatException thrown by DataOutputStream.writeUTF() when serializing a String?
Why is OutOfMemoryError thrown after writing a large number of objects into an ObjectOutputStream?
How can I get the serialVersionUID of a class?
main() { int c[ ]={2.8,3.4,4,6.7,5}; int j,*p=c,*q=c; for(j=0;j<5;j++) { printf(" %d ",*c); ++q; } for(j=0;j<5;j++){ printf(" %d ",*p); ++p; } }
main() { extern int i; i=20; printf("%d",i); }
main() { int i=-1,j=-1,k=0,l=2,a; a=i++&&j++&&k++||l++; printf("%d %d %d %d %d",i,j,k,l,a); }
main() { int c=- -2; printf("c=%d",c); }
#define int char main() { int i=65; printf("sizeof(i)=%d",sizeof(i)); }
main() { int a=10; a=!a>14; Printf ("a=%d",a); }
#include main() { char s[]={'a','b','c','\n','c','\0'}; char *p,*str,*str1; p=&s[3]; str=p; str1=s; printf("%d",++*p + ++*str1-32); }
#include main() { int a[2][2][2] = {{10,2,3,4},{5,6,7,8}}; int *p,*q; p=&a[2][2][2]; *q=***a; printf("%d----%d",*p,*q); }
#include main() { struct xx { int x=3; char name[]="vivek"; }; struct xx *s; printf("%d",s->x); printf("%s",s->name); }
#include main() { struct xx { int x; struct yy { char s; struct xx *p; }; struct yy *q; }; }
main() { printf("\nab"); printf("\bsi"); printf("\rha"); }
main() { int i=5; printf("%d%d%d%d%d%d",i++,i--,++i,--i,i); }
#define square(x) x*x main() { int i; i = 125/square(5); printf("%d",i); }
#define square(x) x*x main() { int i; i = 125/square(5); printf("%d",i); }
main() { char *p="hey friends",*p1; p1=p; while(*p!='\0') ++*p++; printf("%s %s",p,p1); }
main() { char *p="hai friends",*p1; p1=p; while(*p!='\0') ++*p++; printf("%s %s",p,p1); }
#include #define i 10 main() { #define i 50 printf("%d",i); }
#define clrscr() 100 main() { clrscr(); printf("%d\n",clrscr()); }
main() { printf("%p",main); }
main() { clrscr(); } clrscr();
enum colors {BLACK,BLUE,GREEN} main() { printf("%d..%d..%d",BLACK,BLUE,GREEN); return(1); }
void main() { char far *farther,*farthest; printf("%d..%d",sizeof(farther),sizeof(farthest)); }
main() { int i=400,j=300; printf("%d..%d"); }
main() { char *p; p="java"; printf("%c\n",*&*p); }
main() { int i=1; while (i<=5) { printf("%d",i); if (i>2) goto here; i++; } } fun() { here: printf("PP"); }
main() { static char names[5][20]={"pascal","ada","cobol","fortran","perl"}; int i; char *t; t=names[3]; names[3]=names[4]; names[4]=t; for (i=0;i<=4;i++) printf("%s
void main() { int a=5; printf("%d",a++ + ++a); }
void main() { int i=5; printf("%d",i+++++i); }
#include main() { int i=1,j=2; switch(i) { case 1: printf("GOOD"); break; case j: printf("BAD"); break; } }
main() { int i; printf("%d",scanf("%d",&i)); // value 10 is given as input here }
#define f(g,g2) g##g2 main() { int var12=100; printf("%d",f(var,12)); }
main() { int i=0; for(;i++;printf("%d",i)) ; printf("%d",i); }
#include main() { char s[]={'a','b','c','\n','c','\0'}; char *p,*str,*str1; p=&s[3]; str=p; str1=s; printf("%d",++*p + ++*str1-32); }
#include main() { struct xx { int x=3; char name[]="hello"; }; struct xx *s=malloc(sizeof(struct xx)); printf("%d",s->x); printf("%s",s->name); }
#include main() { struct xx { int x; struct yy { char s; struct xx *p; }; struct yy *q; }; }
main() { extern int a; a=20; printf("%d",sizeof(a)); }
main() { printf("%d", out); } int out=100;
main() { printf("%d", out); } int out=100;
main() { extern out; printf("%d", out); } int out=100;
#include main() { struct xx { int x=3; char name[]="hello"; }; struct xx *s=malloc(sizeof(struct xx)); printf("%d",s->x); printf("%s",s->na
#include main() { struct xx { int x=3; char name[]="hello"; }; struct xx *s=malloc(sizeof(struct xx)); printf("%d",s->x); printf("%s",s->name); }
#include main() { struct xx { int x; struct yy { char s; struct xx *p; }; stru
#include main() { struct xx { int x; struct yy { char s; struct xx *p; }; stru
main() { extern int i; i=20; printf("%d",sizeof(i)); }
main() { printf("%d", out); } int out=100;
main() { show(); } void show() { printf("I'm the greatest"); }
main( ) { int m[2][3][2] = {{{2,4},{7,8},{3,4}},{{2,2},{2,3},{3,4}}}; printf("%u %u %u %d \n",m,*m,**m,***m); printf("%u %u %u %d \n",m+1,*m+1,**m+1,***m+1); }
main( ) { int a[ ] = {10,20,30,40,50},j,*p; for(j=0; j<5; j++) { printf(�%d� ,*a); a++; } p = a; for(j=0; j<5; j++) {
main( ) { static int a[ ] = {0,1,2,3,4}; int *p[ ] = {a,a+1,a+2,a+3,a+4}; int **ptr = p; ptr++; printf(�\n %d %d %d�, ptr-p, *ptr-a, **ptr); *ptr++; printf(
main( ){ static int a[ ] = {0,1,2,3,4}; int *p[ ] = {a,a+1,a+2,a+3,a+4}; int **ptr = p; ptr++; printf(�\n %d %d %d�, ptr-p, *ptr-a, **ptr); *ptr++; printf(�\n %d %d %d�, ptr-p
Question : what is the difference between parameter and argument?
What is the difference between class and structure?
What is the difference between an object and a class?
Difference between realloc() and free()?
What is a template?
What is virtual constructors/destructors?
What is the difference between operator new and the new operator?
Difference between "C structure" and "C++ structure".
What is the difference between "overloading" and "overriding"?
Difference between a "assignment operator" and a "copy constructor"
What is the advantage of function overloading according to users point of view?