Question 1

Which of the following is not a control statement in C#

Accepted Answer

"Loop" is not a control statement in C#. In C#, "loop" is not a keyword and it is not used as a control statement. The correct control statements are do…while, for, switch, if…else, and while.

Question 2

The for repetition statement handles the details of counter-controlled repeti
tion.

Accepted Answer

The for repetition statement iterates a specific number of times with a counter-controlled repetition.

Question 3

Consider the following two C# code segments:
Segment 1 Segment 2
Int i = 0;
For (int i=0;i < = 20;++i)
While (i < 20) {
{ Console.WriteLine (i);
++i; }
Console.WriteLine (i);
}
Which of the following statements is true

Accepted Answer

Segment 1 initializes i to 0 and has a for loop that increments i up to and including 20, printing out each value of i along the way. Segment 2 initializes i to 0 outside of the while loop, but then declares and initializes a new i variable inside the while loop. This means the scope of i is different for the two segments. Additionally, since the for loop in Segment 1 will run one extra time (printing out the value of 20), the output from these segments is not the same. Therefore, both (a) and (b) are true.

Question 4

The first line of the for statement is sometimes called the:

Accepted Answer

The first line of the for statement that includes the keyword "for", the initialization of the loop variable, the condition, and any increment or decrement steps is called the for statement header.

Question 5

Which of the following for-loop control headers results in equivalent numbers of iterations:
1)for (int q = 1;q < = 100;++q)
2)for (int q = 100;q >= 0;--q)
3)for (int q = 99;q > 0;q -= 9)
4)for (int q = 990;q > 0;q -= 90)

Accepted Answer

Both loops 3 and 4 decrement by a fixed amount and will iterate 11 times.

Question 6

Modifying the control variable of a for statement in the body can cause errors.

Accepted Answer

Modifying the control variable of a for statement in the body can cause errors because it can affect the number of iterations of the loop and potentially lead to infinite loops or missed iterations.

Question 7

Which of the following for headers is syntactically incorrect

Accepted Answer

A for loop header typically consists of three parts: initialization, condition, and increment/decrement. Option A has all three parts, Option B has only the condition, and Option C is missing the keyword "for" and the initialization and increment/decrement clauses. Therefore, Option C is syntactically incorrect. Option D is not valid because only one option is correct.

Question 8

If a while condition is never true,the body will never execute.

Accepted Answer

If the condition in a while loop is never true, the loop body will not execute even once because the condition is checked before the first iteration.

Question 9

The header for (int i = 0;i < = 10;++i)will cause i to be incremented:

Accepted Answer

The increment part of the loop header (++i in this case) is executed after the entire body of the loop executes and before the next iteration's condition check.

Question 10

Only one control variable may be initialized,incremented or decremented in a for statement header.

Accepted Answer

Multiple initialization,increment or decrement expressions may be included in for statements as comma-separated lists.

Question 11

A while statement automatically increments a variable that a programmer specifies.

Accepted Answer

The while statement does not automatically increment a value-it tests a con

Question 12

A common logic error known as a(n)occurs when the programmer incor
Rectly specifies a conditional operator,such as < instead of < =.

Accepted Answer

An off-by-one error occurs when the programmer incorrectly specifies a boundary or limit in a loop or an array, for example by using < instead of <= or vice versa. A syntax error is a mistake in the format or structure of code, while a fatal error is a severe error that causes the program to crash or terminate abruptly. Thus, the most appropriate choice for the given description is off-by-one error.

Question 13

Counting loops should be controlled with whatever data type most closely reflects the operations taking place,whether that is an int,float or double.

Accepted Answer

Integers should be used to control counting loops,because the approximate nature of floating-point values may prevent loop-continuation conditions from evaluating correctly.

Question 14

A variable used as a counter should be initialized when it's declared.

Accepted Answer

It is good practice to initialize a counter variable to a start value when it is declared. This ensures that the counter starts at a known value and avoids any potential errors that might occur if the variable is used before it is initialized.

Question 15

Counting loops should be controlled with values.

Accepted Answer

Counting loops should be controlled with integers, as they need to iterate a specific number of times. While doubles could also work, they may not be as precise or necessary for loop control. Chars are meant for representing single characters or small integers, not for loop control.

Question 16

Counter-controlled repetition requires only a control variable,an initial value for the control variable and an increment or decrement.

Accepted Answer

Counter-controlled repetition also requires a loop-continuation condition to determine whether the loop should continue executing the statements in its body.

Question 17

The initialization expression,condition and increment expression in a for statement's header must be separated with commas.

Accepted Answer

These expressions must be separated by semicolons;otherwise,a syntax error occurs.

Question 18

A control variable that's declared in a for statement header is not accessible outside of the body of the for statement.

Accepted Answer

The scope of a variable declared in a for statement header is limited to the body of the for loop. It cannot be accessed outside of the loop.

Question 19

for statements cannot be represented as while statements.

Accepted Answer

All for statements can be represented as while statements.

Question 20

Unary operators (such as ++)cannot be used in conditions.

Accepted Answer

Unary operators can be used in conditions.

Quiz 6: Control Statements: Part 2