Bypass loop body on false
If the value of the character stored in temp does not fall outside the range of 65 through 90 inclusive, the conditional clause returns false.
In this case, the while loop terminates, bypassing the body of the loop, and control transfers to the code shown in Listing 3.
The code in Listing 3 prints a thank-you message similar to the last line of output shown earlier.
Then the program terminates.