In Go, as in any other programming language, one builds large programs from a small
set of basic constructs. Variables store values. Simple expressions
are combined into larger ones with operations like
addition and subtraction. Basic
types are collected into aggregates like arrays and structs.
Expressions are used in statements whose execution order is determined by
control-flow statements like if and for. Statements are
grouped into functions for isolation and reuse. Functions are
gathered into source files and packages.
We saw examples of most of these in the previous chapter. In this chapter, we’ll go into more detail about the basic structural elements of a Go program. The example programs are intentionally simple, so we can focus on the language without getting sidetracked by complicated algorithms or data structures.