Usage of Thread. Join ()

When the join method of another thread is called in the first thread, the thread is blocked until the end of the other thread.
For example

1 using System;
2
3 namespace TestThreadJoin
4 {
5 class Program
6 {
7 static void Main ()
8 {
9 System. Threading. Thread x = new System. Threading. Thread (new System. Threading. ThreadStart (f1 ));
10 x. Start ();
11 Console. WriteLine ("This is Main. {0}", 1 );
12 x. Join ();
13 Console. WriteLine ("This is Main. {0}", 2 );
14 Console. ReadLine ();
15}
16 static void f1 ()
17 {
18 System. Threading. Thread y = new System. Threading. Thread (new System. Threading. ThreadStart (f2 ));
19 y. Start ();
20 y. Join ();
21 Console. WriteLine ("This is F1. {0}", 1 );
22}
23
24 static void f2 ()
25 {
26 Console. WriteLine ("This is F2. {0}", 1 );
27}
28}
29}
There are three threads processing (including the main thread). You can check the execution result.
Result:
This is Main.1
This is F2.1
This is F1.1
This is Main.2

If: Comment // x. Join ();
Result:
This is Main.1
This is Main.2
This is F2.1
This is F1.1