Nested Structures
Learn Java nested structures by building a Weekly Meal Planner that organizes meals by day and type, calculates daily and weekly calorie totals.
The project
You’ve been tracking calories by day and meal type, but now you want to see the whole week’s nutrition in one system. Instead of running your tracker day by day, you need a planner that stores all 7 days of meals, calculates per-meal totals, and shows both daily summaries and a weekly summary.
Type the following:
Day 1 Breakfast: 400Day 1 Lunch: 600Day 1 Dinner: 300
It is useful, but it doesn’t give you a complete weekly overview. What you need is a nested structure, a way to combine HashMap and ArrayList so data is organized by day and meal category.
We’ll build a Weekly Meal Planner that organizes meals by day (keys), meal type (sub-keys), and calories (lists). Then, we’ll calculate per-meal totals, daily totals, and the final weekly total.
The programming concept
The programming concept for today is nested structures.
A nested structure means putting one data ...