Question

Which of the following statements is TRUE?

• A for loop executes indefinitely if the loop condition is always false.
• If the loop condition in a for loop is initially false, the loop body does not execute.
• C++ does not allow you to use fractional values for loop control variables that are real numbers.
• In a for statement, if the loop condition is omitted, it is assumed to be false.

Answer 1

• A for loop executes indefinitely if the loop condition is always false. ----> This statement is FALSE. In for loop, the loop condition is checked at the starting of the loop. If the loop condition is true, then only the code inside the loop executes, if the condition is false, then the loop terminates then and there and no other condition in the future is checked.

• If the loop condition in a for loop is initially false, the loop body does not execute. ----> This statement is TRUE and the reason is same as given above. the loop condition is checked at the starting of the loop in the for loop, so if the condition is initially false, the loop terminates without entering into the loop body.

• C++ does not allow you to use fractional values for loop control variables that are real numbers. ----> This statement is FALSE. C++ allows fractional or floating point values in the loop body. There are some risks that maybe the loop will run for less/more cycles than it should but C++ does allow it without giving any compile time error. The program may throw a warning to alert the user.

• In a for statement, if the loop condition is omitted, it is assumed to be false. ----> This statement is FALSE. In C++, if we are not specifying the loop condition, it means that we want the loop condition to be taken as "true" for every iteration without making it false even once. Hence by default, it is assumed as a true condition. In such case loop evaluates to true everytime for each iteration and may go in infinite loop. To save it from going in infinite loop, we need to specifiy some halting conditions to make the program stop running any further.