For Loops

Go keeps the three-part C-style for loop (init; condition; post) just like JavaScript. Go has no separate while or do-while — for is the only looping keyword, and since Go 1.22 it also has a range form for looping a fixed number of times. Rust never had a C-style for — a range (0..6) has been the only way to loop a number of times since Rust 1.0. Swift used to have a C-style for but removed it entirely in Swift 3.0 (SE-0007), also moving to ranges. Java still keeps the C-style for, just like JavaScript.

The C-style loop and range-over-int

for (let i = 0; i <= 5; i++) {
  console.log(i)
}

package main
 
import "fmt"
 
func main() {
	for i := 0; i <= 5; i++ {
		fmt.Println(i)
	}
 
	// range over an integer to loop a fixed number of times
	for i := range 6 {
		fmt.Println(i)
	}
}

fn main() {
    for i in 0..=5 {
        println!("{i}");
    }
 
    // Rust has no three-part C-style for — a range is the only way to loop a fixed number of
    // times, and has existed since Rust 1.0 (Go only added range-over-int in 1.22)
    for i in 0..6 {
        println!("{i}");
    }
}

for i in 0...5 {
    print(i)
}
 
// Swift removed the C-style for entirely in Swift 3.0 (SE-0007) — a range is the standard way
// to loop, the same idea as the range-over-int Go only added in 1.22
for i in 0..<6 {
    print(i)
}

void main() {
    for (int i = 0; i <= 5; i++) {
        IO.println(i);
    }
 
    // Java has no range-over-int syntax like Go 1.22+; the closest thing is IntStream.range(...)
    IntStream.range(0, 6).forEach(IO::println);
}

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