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See why your substring answer is off by one

Practice: Asking for a format you can use. About 5 minutes.

About this exercise

Your answer to a Java practice question was "MPUT" but the key says otherwise. Ask for exactly 3 numbered lines: line 1 lists every letter of COMPUTER with its index like 'C0 O1 M2 ...'; line 2 starts 'Takes:' and says which indexes substring(2, 5) uses; line 3 starts 'Result:' with the right answer in quotes and what you included by mistake. No code blocks, under 60 words.

Common mistakes when you ask AI for this

  • Getting a lecture. The AI explains String methods in general instead of your exact mistake. Try: Say: "Exactly 3 numbered lines."
  • No index map. Without seeing each letter's index, it's hard to see where you went off. Try: Ask: "Line 1: every letter with its index, like C0 O1 M2."
  • No labels. Unlabeled lines blur the rule and the answer together. Try: Add: "Line 2 starts 'Takes:', line 3 starts 'Result:'."
  • Code you didn't need. The AI may write a whole Java program to demonstrate. Try: Add: "No code."

What a strong prompt includes

  • Sets the number of lines
  • Asks for an index map
  • Gives the labels
  • Asks what you got wrong
  • Rules out code

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