while

This tests the condition at the top.

while (inumber < 5) 
{ 
   inumber++; 
   break; 
} 

Continue

The continue statement transfers execution to the next iteration within the loop

while (inumber < 5) 
{ 
   if (true) { 
      continue; 
   } 
} 

Single Statement

When you only have a single statement the curly bracket is optional.

while (inumber < 5) 
   Console.WriteLine(inumber);  

is the same as

while (inumber < 5) 
{ 
   Console.WriteLine(inumber);  
} 

No Statements

There might be a situation when there are no expressions in the loop.

while ((myString = Function_ReturnsString()) == "text") 
{ 
} 

It is possible to write this as one line including a semi-colon although this just looks confusing.

while ((myString = Function_ReturnsString()) == "text") ;