Python Contiguous Arrays & Multi-Dimensional Matrices
An array in C is a sequence of elements stored in unbroken contiguous memory addresses. Element access arr[i] computes instantly via base_address + (i * sizeof(type)). Calculate array length using sizeof(arr) / sizeof(arr[0]) at declaration scope.
"An array is a row of contiguous lockers in a gym: once you know locker #0 is at address 1000 and each locker is 4 feet wide, locker #3 is guaranteed to be at address 1012."
Deep Dive: How It Works
Contiguous Storage: Elements are laid out side-by-side in linear memory without gaps.
Sizeof Calculation: sizeof(scores) / sizeof(scores[0]) computes total element count.
Row-Major 2D Matrices: 2D arrays are stored row-by-row in linear RAM.
Syntax Blueprint
int scores[4] = {88, 92, 79, 95};
size_t count = sizeof(scores) / sizeof(scores[0]);Declare fixed-size array and calculate element count using compile-time sizeof.
Core Rules to Remember
Common Beginner Traps & How to Fix Them
Using sizeof(arr) / sizeof(arr[0]) inside a function where arr was passed as a parameter.Why it happens: In functions, arrays decay to pointers, so sizeof(arr) returns the pointer size (8 bytes), not the full array.
How to fix: Always pass the array length as an explicit size_t length parameter to functions.
Live Interactive Example
Hit Run Code to see it liveYour Turn: Micro Challenge
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Calculate Array Size with sizeof
- Print "Total Elements: %zu\n" calculated using the sizeof idiom: sizeof(scores) / sizeof(scores[0]).
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