Question

5C++ Questions

1. What will the following code print?
num = 8;
cout << --num << " ";
cout << num++ << " ";
cout << num;

2.Since the while loop evaluates the condition before executing the statement(s), it is known as a(n)____ loop, whereas the do-while loop evaluates the condition after the statements have been executed, it is known as a(n)____ loop.

3.T/F While loops can only be used when a counter is decremented to zero. If the counter is incremented you must use the do-while loop.

4.How many times will the following program print Hello?

counter = 3; 
while (counter > 0) {
    loop = 5;
    while (loop > 0) {
          cout << "Hello" << endl;
          loop--;
     }
     counter--;
}

5.If nothing within a while loop causes the condition to become false, a(n) ________ may occur.

6.The -- operator ... (check all that apply)

		subtracts one from the value of its operand.
		must have an lvalue, such as a variable, as its operand.
		can be used in either prefix or postfix mode.
		is a unary operator.

7.Which of the following statements will result in an infinite loop.

		x = 10; while (x >= 0) { cout << x; ++x; }
		x = 10; while (x >= 0) { cout << x; }
		x = 0; while (x <= 10) { cout << x; x = 10; }
		x = 10; while (x >= 0); { cout << x; x--; }

8.T/F In C++, a file must be opened before the contents can be read.

9. T/F In C++, a file must exists before it can be written to.

10.Which of the following statements show the proper way to use the increment (++) operator.

		x++ = 1023;
		x = 23++;
		y = ++x;
		counter--;

Answer 1

Question 1:
Output of the code 7 7 8
Answer:
7 7 8

Question 2:
Since the while loop evaluates the condition before executing the statement(s), it is known as a(n) pre condition loop, whereas the do-while loop evaluates the condition after the statements have been executed, it is known as a(n) pre condition loop.
Answer:
pre condition
post condition

Question 3:
While loops can only be used when a counter is decremented to zero. If the counter is incremented you must use the do-while loop.
Answer:
False

Question 4:
Number of times will the following program print Hello is 15
Answer:
15

Question 5:
If nothing within a while loop causes the condition to become false, a(n) infinite loop may occur.
Answer:
infinite loop

Question 6:
The -- operator can be used in either prefix or postfix mode.
Answer:
can be used in either prefix or postfix mode.

Question 7:
x = 10;
while (x >= 0) {
    cout << x;
    ++x;
}
x = 10;
while (x >= 0) {
    cout << x;
}
x = 0;
while (x <= 10) {
    cout << x;
    x = 10;
}
will result in an infinite loop
Answer:
Options 1,2,3

Question 8:
In C++, a file must be opened before the contents can be read.
Answer:
True

Question 9:
In C++, a file must exists before it can be written to.
Answer:
False

Question 10:
statements show the proper way to use the increment (++) operator is y = ++x;
Answer:
y = ++x;