11 lines
1.4 KiB
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11 lines
1.4 KiB
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<!doctype html><html lang="en"><meta charset="utf-8"><title>Collections and repeated work</title><h1>Collections and repeated work</h1><p>15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.</p><p>A collection stores related values. The loop visits 1, 2, and 3, updating the total from 0 to 1, then 3, then 6. Record this trace rather than guessing. Identify the first and last valid positions in this language: Pascal can declare a 1-based array, while many other examples use zero-based containers. Add another value and update the bounds correctly. Explain what an empty collection should produce.</p><p>Line numbers describe program order. <code>GOSUB</code> visits a subroutine and <code>RETURN</code> resumes the caller. <code>SYSTEM</code> exits this interpreter. BASIC dialects differ: a 6502 or Z80 computer does not automatically run this exact dialect.</p><pre><code class="language-basic">10 DIM M(3)
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20 LET M(1)=1
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30 LET M(2)=2
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40 LET M(3)=3
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50 LET T=0
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60 FOR I=1 TO 3
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70 LET T=T+M(I)
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80 NEXT I
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90 PRINT T
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100 SYSTEM
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</code></pre><p><strong>Expected result:</strong> <code>6</code></p><h3>Practice and evidence</h3><p>Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.</p><p><a href="https://packages.ubuntu.com/noble/bwbasic">Language reference</a></p></html> |