Go Data Structures

Slices and maps look simple and hide the sharpest edges in the language. These rules prevent the aliasing, nil, and iteration bugs that survive code review.

1. Nil Slice vs Empty Slice

var a []int          // nil slice — len 0, cap 0, no allocation
b := []int{}         // empty slice — len 0, allocated header
c := make([]int, 0)  // empty slice — same as b