Pseudocode FOR ... TO ... NEXT loop

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Quick Questions

Shade in the A or B circle for each question.

1. Which line correctly starts a loop that repeats 5 times in Cambridge pseudocode?

A FOR Count ← 1 UNTIL 5

B FOR Count ← 1 TO 5

2. Which line correctly closes the loop FOR Count ← 1 TO 10?

A NEXT Count

B ENDFOR Count

3. A FOR loop starts with FOR Count ← 1 TO 10. What does the NEXT Count line do?

A It adds 1 to Count and goes back to the top of the loop

B It stops the loop straight away

4. How many times does the loop body run? FOR Count ← 1 TO 10

A 9 times

B 10 times

5. Which FOR loop is written correctly?

A FOR Count ← 1 TO 10 OUTPUT Count NEXT Count

B FOR Count ← 1 TO 10 OUTPUT Count NEXT Total

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1FOR Count ← 1 TO 5		AThe statement inside the loop is not indented. The loop body should be indented, e.g. 3 spaces before OUTPUT Count.
2NEXT Count		BFOR Number ← 1 TO 10 OUTPUT "Hello" NEXT Number
3A FOR loop that counts from 1 to 3 and outputs the counter each time, with the loop body indented		CStarts a count-controlled loop where Count begins at 1 and goes up to 5, so the loop body repeats 5 times
4A FOR loop that repeats an action exactly 10 times, using the same variable name after NEXT		DFOR Count ← 1 TO 3 OUTPUT Count NEXT Count
5FOR Count ← 1 TO 5 OUTPUT Count NEXT i		ENEXT uses a different variable name (i) from the one in the FOR line (Count). It should be NEXT Count.
6FOR Count ← 1 TO 5 OUTPUT Count NEXT Count		FMarks the end of the FOR loop and adds 1 to Count before the loop checks whether to repeat again

Definitions

FOR Count ← 1 TO 10

Fill in the Blanks

Complete each line of code by filling in the missing parts.

___ Count ← 1 TO 10 OUTPUT Count NEXT Count

FOR Count ← 1 TO 10 OUTPUT Count ____ Count

FOR Num ← 1 __ 5 OUTPUT "Hi" NEXT Num

FOR Count ← 1 TO _ // repeat 3 times OUTPUT "Go" NEXT Count

FOR Num ← 1 TO 4 OUTPUT Num * 2 NEXT ___

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A Total ← 0

B FOR Count ← 1 TO 5

C Total ← Total + Count

D NEXT Total

E OUTPUT Total

Question 2

A FOR Count ← 1 UNTIL 10

B OUTPUT Count

C NEXT Count

Question 3

A Total ← 0

B FOR Number ← 5 TO 1

C INPUT Mark

D Total ← Total + Mark

E NEXT Number

Question 4

A OUTPUT "Start"

B FOR Count ← 1 TO 3

C OUTPUT Counter * 2

D NEXT Count

Question 5

A Total ← 0

B FOR Count ← 1 TO 10

C Total = Total + Count

D NEXT Count

Answer Key

Pseudocode FOR ... TO ... NEXT loop

Section A: Quick Questions

B — FOR Count ← 1 TO 5

A — NEXT Count

A — It adds 1 to Count and goes back to the top of the loop

B — 10 times

A — FOR Count ← 1 TO 10 OUTPUT Count NEXT Count

Section B: Match the Pairs

FOR Count ← 1 TO 5 → Starts a count-controlled loop where Count begins at 1 and goes up to 5, so the loop body repeats 5 times

NEXT Count → Marks the end of the FOR loop and adds 1 to Count before the loop checks whether to repeat again

A FOR loop that counts from 1 to 3 and outputs the counter each time, with the loop body indented → FOR Count ← 1 TO 3 OUTPUT Count NEXT Count

A FOR loop that repeats an action exactly 10 times, using the same variable name after NEXT → FOR Number ← 1 TO 10 OUTPUT "Hello" NEXT Number

FOR Count ← 1 TO 5 OUTPUT Count NEXT i → NEXT uses a different variable name (i) from the one in the FOR line (Count). It should be NEXT Count.

FOR Count ← 1 TO 5 OUTPUT Count NEXT Count → The statement inside the loop is not indented. The loop body should be indented, e.g. 3 spaces before OUTPUT Count.

Section C: Definitions

FOR Count ← 1 TO 10 — A count-controlled loop that repeats the indented statements a fixed number of times, with Count going from 1 to 10. NEXT Count closes the loop and moves Count up by 1.

Section D: Fill in the Blanks

FOR Count ← 1 TO 10
    OUTPUT Count
NEXT Count

FOR Count ← 1 TO 10
    OUTPUT Count
NEXT Count

FOR Num ← 1 TO 5
    OUTPUT "Hi"
NEXT Num

FOR Count ← 1 TO 3 // repeat 3 times
    OUTPUT "Go"
NEXT Count

FOR Num ← 1 TO 4
    OUTPUT Num * 2
NEXT Num

Section E: Spot the Error

D — NEXT must use the same variable as the FOR line. The loop counter is Count, so the line should be NEXT Count.

A — A FOR loop uses the keyword TO between the start and end values. UNTIL belongs to REPEAT ... UNTIL. It should be FOR Count ← 1 TO 10.

B — A FOR loop counts up from the start value to the end value. With 5 TO 1 the start is bigger than the end, so the loop would not run. It should be FOR Number ← 1 TO 5.

C — The loop variable is Count, so the body must use Count. Counter is a different variable that has no value. It should be OUTPUT Count * 2.

C — Cambridge pseudocode uses the assignment arrow ←, not =. The line should be Total ← Total + Count.