Game 5 Unit 2 of 8 1 hr learning time

How Long Is a Word?

Use LEN to count letters and draw blue tiles — one per character, centred on screen.

25% of Word Scramble

The game screen shows a word, but it just sits there as plain text. Word Scramble needs something more — a row of blue tiles, one per letter, centred on screen. To draw the right number of tiles, the program needs to know how long the word is.

LEN — Counting Characters

  10 LET w$="cat"
  20 PRINT w$;" has ";LEN w$;" letters"
  30 LET w$="planet"
  40 PRINT w$;" has ";LEN w$;" letters"
  50 LET w$="adventure"
  60 PRINT w$;" has ";LEN w$;" letters"

LEN w$ returns the number of characters in a string. “cat” has 3, “planet” has 6, “adventure” has 9. Spaces count too — LEN "hi there" is 8. An empty string "" has a length of 0.

LEN isn’t just a fact about a string — it’s a tool. If you know how long a word is, you can draw the right number of tiles, centre them on screen, and loop through each character position.

Drawing Tiles

   5 BORDER 0: PAPER 0: INK 7: CLS
  10 FOR i=0 TO 31
  12 PRINT AT 0,i; PAPER 2;" "
  14 NEXT i
  16 PRINT AT 0,8; PAPER 2; INK 7; BRIGHT 1;" WORD SCRAMBLE "
  20 PRINT AT 4,10; INK 5;"Unscramble:"
  30 LET w$="cat"
  32 LET c=(32-LEN w$*2)/2
  34 FOR i=1 TO LEN w$
  36 PRINT AT 8,c+i*2-2; PAPER 1;" "
  38 PRINT AT 9,c+i*2-2; PAPER 1;" "
  40 NEXT i

Three blue tiles centred on a black screen — one per letter of cat

Three blue squares appear in the middle of the screen. Change w$ to “planet” and six tiles appear. Change it to “adventure” and nine tiles fill a wider space — always centred.

Here’s how the centring works:

  • Each tile takes 2 columns: one for the letter, one gap
  • A word of length L needs L * 2 columns
  • The starting column is (32 - L * 2) / 2
  • Tile i sits at column c + i * 2 - 2

The FOR loop on lines 34-40 draws two rows of blue (PAPER 1) spaces for each letter position. Two rows tall makes the tiles feel solid, not like thin underlines.

Try This

Longer words. Change w$ to “strawberry” (10 letters) or “hippopotamus” (12). Watch the tiles stretch across the screen. At what length do they run out of space?

Different colour. Replace PAPER 1 with PAPER 3 (magenta) or PAPER 4 (green). Pick the colour that looks best against the black background.

What You’ve Learnt

  • LEN — returns the number of characters in a string
  • LEN in a loop — FOR i = 1 TO LEN w$ runs once per character
  • Centring formula — (32 - LEN w$ * 2) / 2 finds the starting column
  • Coloured tiles — PAPER inside PRINT AT creates coloured blocks