FOR ... TO ... NEXT loop (7a)

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Quick Questions

Shade in the A or B circle for each question.

1. How many times does the body of FOR Count ← 1 TO 5 run?

A 5 times

B 4 times

2. Which line correctly ends the loop that starts with FOR Index ← 1 TO 30?

A ENDFOR Index

B NEXT Index

3. How many times does FOR Num ← 4 TO 4 run?

A Once

B Never

4. What happens when FOR Num ← 10 TO 1 is run?

A The body does not run at all

B It counts down from 10 to 1

5. Which data type must the loop variable in a FOR loop have?

A STRING

B INTEGER

Match the Pairs

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

Left column		Right column
1FOR Index ← 1 TO 30		AFOR Index ← 10 TO 1
2FOR Count ← 5 TO 5		BRuns the loop body exactly once, because the start value and end value are equal
3A FOR loop must be closed with NEXT followed by the same loop variable		CFOR Index ← 1 TO 30 OUTPUT Index NEXT Index
4The loop does not run at all if the start value is bigger than the end value		DA FOR loop must end with NEXT Index, not ENDFOR. ENDFOR is not Cambridge pseudocode.
5FOR Index ← 1 TO 30 OUTPUT Index ENDFOR		ERepeats the statements below once for each integer from 1 to 30 inclusive, ending at NEXT Index
6FOR Index ← 1 TO 30 OUTPUT Index NEXT Count		FThe NEXT line uses a different identifier (Count) from the loop variable (Index).

Definitions

FOR Index ← 1 TO 30

Fill in the Blanks

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

FOR Index ← 1 __ 30 OUTPUT Index NEXT Index

FOR Index ← 1 TO 30 OUTPUT Index ____ Index

FOR Index _ 1 TO 30 OUTPUT Index NEXT Index

DECLARE Index : _______ FOR Index ← 1 TO 30 NEXT Index

FOR Index ← 1 TO _ OUTPUT "Hello" NEXT Index

Spot the Error

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

Question 1

A DECLARE Index : INTEGER

B FOR Index ← 1 TO 3

C OUTPUT Index

D ENDFOR

Question 2

A FOR Index ← 1 UNTIL 10

B OUTPUT Index * 2

C NEXT Index

Question 3

A DECLARE Total : INTEGER

B Total ← 0

C FOR Index = 1 TO 4

D Total ← Total + Index

E NEXT Index

Question 4

A DECLARE Index : INTEGER

B OUTPUT "Start"

C FOR Index ← 1.5 TO 5

D OUTPUT Index

E NEXT Index

Question 5

A DECLARE Num : INTEGER

B FOR Num ← 1 TO 3

C OUTPUT Index * Index

D NEXT Num

Answer Key

FOR ... TO ... NEXT loop (7a)

Section A: Quick Questions

A — 5 times

B — NEXT Index

A — Once

A — The body does not run at all

B — INTEGER

Section B: Match the Pairs

FOR Index ← 1 TO 30 → Repeats the statements below once for each integer from 1 to 30 inclusive, ending at NEXT Index

FOR Count ← 5 TO 5 → Runs the loop body exactly once, because the start value and end value are equal

A FOR loop must be closed with NEXT followed by the same loop variable → FOR Index ← 1 TO 30 OUTPUT Index NEXT Index

The loop does not run at all if the start value is bigger than the end value → FOR Index ← 10 TO 1

FOR Index ← 1 TO 30 OUTPUT Index ENDFOR → A FOR loop must end with NEXT Index, not ENDFOR. ENDFOR is not Cambridge pseudocode.

FOR Index ← 1 TO 30 OUTPUT Index NEXT Count → The NEXT line uses a different identifier (Count) from the loop variable (Index).

Section C: Definitions

FOR Index ← 1 TO 30 — Repeats the code once for each integer from 1 to 30 inclusive, up to NEXT Index. Runs once if both values are equal and not at all if the start value is bigger.

Section D: Fill in the Blanks

FOR Index ← 1 TO 30
    OUTPUT Index
NEXT Index

FOR Index ← 1 TO 30
    OUTPUT Index
NEXT Index

FOR Index ← 1 TO 30
    OUTPUT Index
NEXT Index

DECLARE Index : INTEGER
FOR Index ← 1 TO 30
NEXT Index

FOR Index ← 1 TO 1
    OUTPUT "Hello"
NEXT Index

Section E: Spot the Error

D — A FOR loop in Cambridge pseudocode ends with NEXT followed by the loop variable, not ENDFOR. It should be NEXT Index.

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

C — The loop variable is given its start value with the assignment arrow ←. The = sign is a comparison operator. It should be FOR Index ← 1 TO 4.

C — The loop variable must be an INTEGER, so the start value cannot be a decimal such as 1.5. It should be FOR Index ← 1 TO 5.

C — The loop variable is Num, so the body must use Num. Index has not been declared or given a value. It should be OUTPUT Num * Num.