ICDL Coding Principles (ICDL) case studies
ICDL Coding Principles · Put your knowledge to work in context.
The ICDL Coding Principles credential sits within the ICDL family of digital-skills certifications, aimed at learners who want a recognised starting point in computer programming rather than a vendor-specific developer qualification. It suits school and college students, career changers, and employees whose roles increasingly touch automation, scripting, or software-adjacent work. The ICDL Coding Principles case studies are 5 cases and about 2,354 words.
1The Temperature Logger That Skips Readings
A technician writes a program to read a sensor once per second for 60 seconds and store each reading in an array indexed 0 to 59. The loop counter starts at 1 and runs while counter <= 60, storing the reading at position counter .
520 words, about 3 min2Discount Logic That Gives Money Away
An online shop applies discounts with this rule set: orders of 100 or more get 10% off; orders of 200 or more get 20% off; orders of 500 or more get 30% off. The programmer writes three separate if statements (not else if ), each subtracting its percentage from the running total.
478 words, about 2 min3Search That Never Terminates
A student writes a linear search to find a target value in a list of 10,000 unsorted numbers. The loop is written as: start at index 0, and while list[i] != target: i = i + 1 .
392 words, about 2 min4The Report That Counts Wrong
A payroll script sums a list of daily hours for each employee. Each employee's hours are stored as strings (e.g., "8", "7.5").
476 words, about 2 min5Feature Creep in a Small Utility
A developer is asked to build a small tool that renames image files to a sequential pattern (img 001, img 002, ...). During development, three new requests arrive: also resize images, also upload them to a cloud folder, and also generate a web gallery page.
488 words, about 2 min