Unit 4 - Iteration

Question 1

iteration statements

Answer 1

Change the flow of control by repeating a set of statements zero or more times until a condition is met

Question 2

Loop

Answer 2

Repetition of statements

Repeating a series of steps over & over and over

Question 3

Structure of while loop

Answer 3

while (/*Boolean expression/*)
{
      //statement one;
      //statement two;
      // ...
}

Question 4

Loop control variable

Answer 4

//initialize LCV
while (/* check LCV*/)
{
      //statement one;
      //statement two;
      //....
      //update loop control variable
}

Question 5

A loop is an infinite loop when

Answer 5

the Boolean expression always evaluate to true

Question 6

If the Boolean expression evaluates to false initially,

Answer 6

the loop body is never executed at all

Question 7

Algorithm to sum individual digits given a number

Answer 7

Using mod, integer division, and while loop to do so

1 - Given an integer called number
2 - Create a variable for the sum
3 - Use mod to isolate the last digit of the number
4 - add the last digit to sum
5 - use integer division to eliminate the last digit from the number
6 - Repeat while there are still digits
7 - display the sum

Question 8

Algorithm to calculate the number of years it would take to reach your goal using Interest

Answer 8

1 - Given an integer called numYears
2 - Create a variable for the total
3 - Add total to total multiplied by 10 years
4 - increase year by one and print out yearly balance
5 - Repeat until total reaches 1000
6 - Display numYears

Question 9

Algorithm to sum first 10 positive multiples of 4

Answer 9

1 - Given an integer called counter
2 - Create a variable for the sum
3 - Add sum to counter multiplied by 4
4- Increase counter by one
5 - Repeat until value reaches 10
6 - Display sum

Question 10

for loop header

Answer 10

3 parts
initialization
Boolean expression
increment or decrement

Question 11

in a for loop, initialization is

Answer 11

only executed once before the first Boolean expression evaluation

Question 12

In each iteration of a for loop, the increment statement is executed after

Answer 12

the entire loop body is executed and before the Boolean expression is evaluated again

Question 13

Structure of a for loop

Answer 13

for (initialization;Boolean expression; update)’

Question 14

a for loop can be rewritten into an

Answer 14

equivalent while loop and vice versa

Question 15

When statements need to repeat a defined number of time, which type is more appropriate?

Answer 15

for loop may be more appropriate as start and end values can be seen on one line

Question 16

When repeating statements an x amount of times or based on complex Boolean expression, which type is more appropriate?

Answer 16

while loop as while statement isolates the Boolean expression

Question 17

When updating to LCV is more complex than a simple increment or decrement, which type is more appropriate?

Answer 17

while loop as you can update LCV over a series of statements to make it more readable

Question 18

OBOE

Answer 18

iteration statement loops one time too many or too few

Question 19

Common mistakes made in initialization

Answer 19

Should a variable start at 0 or 1

Question 20

Common mistakes made in boolean expression

Answer 20

Should we use < or <=

Question 21

Common mistakes made in updating

Answer 21

Should our value increase or decrease by 1 each time

Question 22

How to prevent mistakes

Answer 22

Test loop with small values

THINK

Question 23

Algorithm for finding substring within a String

Answer 23

ggg