Control Flow — if/for Look Similar but There's No while

In Ruby, you loop through arrays with [1,2,3].each { |n| puts n }. Block-passing is second nature.

In Go: for _, n := range []int{1,2,3} { fmt.Println(n) }. No blocks, no iterators. for loops are everything.

No while

Ruby's while condition do ... end becomes for condition { ... } in Go. The keyword is for but it acts like while. Go unified all loops into for.

Infinite loops: for { ... } — Ruby's loop do ... end.

No .map, .select

What Ruby does in numbers.map { |n| n * 2 } takes Go three lines:

result := make([]int, len(numbers))
for i, n := range numbers {
    result[i] = n * 2
}

Go community calls it "explicit." Ruby developers call it "verbose." Both are correct.

No Parentheses in if

Ruby doesn't use parentheses in if conditions. Neither does Go. Similar. But Go's if can include a short statement: if err := doSomething(); err != nil { ... } — a pattern Ruby doesn't have.

switch Is Powerful

Ruby's case/when supports pattern matching. Go's switch is similar but fallthrough is off by default (opposite of C). There's also a type switch — switch v := x.(type) { case int: ... } is similar to Ruby's case x when Integer.