Nested and mixed iteration
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Can a FOR loop be nested inside a WHILE loop?
2. Does each nested loop need its own matching closing keyword?
3. In mixed iteration, does the inner loop run fully for each repetition of the outer loop?
4. Can a WHILE loop be nested inside a FOR loop?
5. If a FOR loop is nested inside a WHILE loop, should it close with END WHILE?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1WHILE total < 10 DO FOR i FROM 1 TO 3 total ← total + i END FOR END WHILE | ACloses the inner FOR loop first, then the outer WHILE loop | |
| 2END FOR followed by END WHILE | BFOR j FROM 1 TO 5 WHILE total < 20 DO | |
| 3Nesting one loop type inside a different loop type | CThe inner WHILE loop must be closed with END WHILE before END FOR | |
| 4A WHILE loop written entirely inside the body of a FOR loop | DMixed iteration | |
| 5WHILE total < 10 DO FOR i FROM 1 TO 3 total ← total + i ENDFOR END WHILE | EA FOR loop nested inside a WHILE loop | |
| 6FOR i FROM 1 TO 3 WHILE total < 5 DO total ← total + i END FOR | FThe inner loop should close with END FOR, not ENDFOR |
C
Definitions
Mixed iteration
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
WHILE total < 10 DO
___ i FROM 1 TO 3
2.
WHILE total < 10 DO
FOR i FROM 1 TO 3
total ← total + i
_______
3.
WHILE total < 10 DO
FOR i FROM 1 TO 3
total ← total + i
END FOR
_________
4.
FOR j FROM 1 TO 5
_____ total < 20 DO
5.
The inner loop runs fully for each _____ of the outer loop
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
WHILE total < 10 DO
B
FOR i FROM 1 TO 3
C
total ← total + i
D
END FOR
E
END LOOP
Question 2
A
FOR j FROM 1 TO 5
B
WHILE total < 20 DO
C
PRINT total
D
total ← total + 1
E
END WHILE
F
END FOR
Question 3
A
WHILE count < 5 DO
B
FOR k FROM 1 TO 2
C
count ← count + 1
D
ENDFOR
E
END WHILE
Question 4
A
FOR i FROM 1 TO 3
B
WHILE total < 15
C
total ← total + i
D
END WHILE
E
END FOR
Question 5
A
total ← 0
B
WHILE total < 10 DO
C
FOR i FROM 1 TO 3
D
total = total + i
E
END FOR
F
END WHILE
Answer Key
Nested and mixed iteration
Section A: Quick Questions
Q1
B — True
Q2
A — True
Q3
B — True
Q4
A — True
Q5
A — False
Section B: Match the Pairs
Q1
WHILE total < 10 DO
FOR i FROM 1 TO 3
total ← total + i
END FOR
END WHILE → A FOR loop nested inside a WHILE loop
Q2
END FOR followed by END WHILE → Closes the inner FOR loop first, then the outer WHILE loop
Q3
Nesting one loop type inside a different loop type → Mixed iteration
Q4
A WHILE loop written entirely inside the body of a FOR loop → FOR j FROM 1 TO 5
WHILE total < 20 DO
Q5
WHILE total < 10 DO
FOR i FROM 1 TO 3
total ← total + i
ENDFOR
END WHILE → The inner loop should close with END FOR, not ENDFOR
Q6
FOR i FROM 1 TO 3
WHILE total < 5 DO
total ← total + i
END FOR → The inner WHILE loop must be closed with END WHILE before END FOR
Section C: Definitions
Q1
Mixed iteration — Nesting one loop type inside a different loop type, such as a FOR loop inside a WHILE loopSection D: Fill in the Blanks
Q1
WHILE total < 10 DO
FOR i FROM 1 TO 3Q2
WHILE total < 10 DO
FOR i FROM 1 TO 3
total ← total + i
END FORQ3
WHILE total < 10 DO
FOR i FROM 1 TO 3
total ← total + i
END FOR
END WHILEQ4
FOR j FROM 1 TO 5
WHILE total < 20 DOQ5
The inner loop runs fully for each cycle of the outer loopSection E: Spot the Error
Q1
E — The outer WHILE loop must be closed with END WHILE, not END LOOP.
Q2
C — VCAA pseudocode uses DISPLAY to output a value, not PRINT.
Q3
D — The closing keyword for the inner loop should be written as END FOR, not ENDFOR.
Q4
B — The WHILE condition is missing DO — it should read WHILE total < 15 DO.
Q5
D — Assignment in pseudocode uses ←, not =.