Programming Logic by Hand: Variables, Trace Tables, Conditions, Loops, Arrays & Strings, Functions, Recursion and Debugging Off-by-One Errors

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Trace an eight-line program in a trace table: you work out a ← a + b from the row above, copy a into a temporary t, finish the swap of a and b and update c with the new b.
• Run a grading chain on seven test cases with IFS, find the branch line each case reaches, evaluate a bonus rule with AND, OR and NOT and measure how many branches the test table covers.
• Trace a for-loop that adds i × bonus to an accumulator, count the passes of a loop with a step, and number every run of the body in a nested loop.
• Peel off the digits of 4,706 with MOD, count how often a halving loop runs before n drops below its limit, fill a missing step of a toy 3n + 1 sequence and read a guard flag that stops a loop after ten steps.
• Trace the running maximum of an eight-element array, convert its position into a 0-based index, read a word backwards character by character with MID and LEN and check whether it is a palindrome.
• Evaluate a function for a table of calls, keep a running total of its return values, and trace a main program in which a procedure with a side effect changes the result of a later call.
• Fill the missing return values in two call-stack tables – a product of 1 … n and a digit sum – trace the same product with a loop and count how deep the digit-sum stack grows.
• Put a buggy and a fixed loop side by side and compute the fixed total, correct a maximum that starts at the wrong value, mark each test as Pass or Fail and chart the bugs found in the club's homework review.