How does a do-while loop differ from a while loop in C?

"C supports do-while loops. Recall that the difference between a while loop and a do-while loop is when the continuation condition is checked. For a while loop it is prior to the beginning of the loop body and in a do-while loop it is at the end of the loop. This means that a do-while always executes at least once. An example can be found in Code Sample 17.4. Note the syntax and style: the opening curly bracket is again on the same line as the keyword do. The while keyword and continuation condition are on the same line as the closing curly bracket. In a slight departure from prior syntax, a semicolon does"