I need to read some article and deeply understand this part. I found many good question on this concept but i am not sure the situation of when to use them?

Second point to read in C in greater detail is concept of sequence point and rvalue and lvalue.

One finer study tells that following statement is absolutely valid.
*((mycondition) ? &var1 : &var2) = myexpression;

Read about function pointer and pragma.... conditional operator...

Also goto can not be used to jump across different function.