Arrays

Array fundamentals, slicing, and common patterns in Go.

5 min readMastering Data Structures & Algorithms for Software Engineering InterviewsCode

Array Basics

Bubble sort — watch comparisons and swaps step by step

Bubble Sort

Step 1 / 51 — Initial array

In Go, arrays have fixed size determined at compile time. They are value types — assignment copies the entire array. Most Go code uses slices (dynamic arrays) instead.

Goarray-declaration-and-initialization.go

18 linesLn 1, Col 1Go

Arrays have fixed size as part of their type. `[3]int` and `[5]int` are different types. Use `...` to infer size from literal.

Slicing and Slices

Slices are the dynamic, flexible view into arrays. A slice has three components: pointer to underlying array, length (visible elements), and capacity (total allocated).

Goslice-creation-and-operations.go

25 linesLn 1, Col 1Go

Slices reference underlying array. Append may reallocate. Copy copies data. Slice expressions create new views.

Common Array Patterns

Two-pointer traversal: Left/right pointers for sorted arrays, palindromes.
In-place modification: Use indices as implicit hash (e.g., negation trick for duplicates).
Prefix sums: Precompute cumulative sums for O(1) range queries.
Sliding window: Maintain window with left/right pointers for subarray problems.
Binary search: On sorted arrays or answer space (monotonic property).

2D Arrays (Matrices)

Gomatrix-representation-and-traversal.go

27 linesLn 1, Col 1Go

Go uses slice of slices for matrices. Row-major order. Direction vectors simplify neighbor traversal.

Mark this lesson complete to store local progress and unlock a cleaner resume path the next time you visit.