1. In which type of loop is the instruction executed at least once?
For While-Do Repeat-Until Such a loop doesn't exist
2. We want to write a program that asks the user to supply a number. The program then should show all the prime numbers up to that number. In this case, the best loop to use is
For While-Do Repeat-Until Other structure
3. What are the two basic rules for nesting of loops?
1: 2:
4. What is the diference between loops of type While-Do and Repeat-Until?
While-Do is for integer numbers, Repeat-Until is for variables of floating point type. Repeat-Until is for integer numbers, While-Do is for variables of floating point type. In loops of type Repeat-Until the condition is checked in the beginning, whereas in loops of type While-Do the condition is checked at the end. In loops of type While-Do the condition is checked in the beginning, whereas in loops of type Repeat-Until the condition is checked at the end.
5. What is wrong with the following code? x := 0.0; while (x<10.0) do begin y := x*x; z := x*y; writeln('The square of ',x:0:2, ' is ', y:0:2); writeln('The cube of ',x:0:2, ' is ', z:0:2); end;
This loop will never finish We should use a loop of Repeat-Until instead. We should use a For-loop instead. The condition cannot contain variables of type real.
6. We want to write a program that asks the user to choose a type of calculation or to exit the program (1=adding, 2=subtracting, 0=finish). It has to continue doing this forever (except, of course when the user selects 0). In this case, the best loop to use is