Continue

A for-loop keeps iterating until it reaches a terminating condition. Unlike break, continue will just stop the current iteration of a loop.

With a label, we can even use continue to go to the next iteration of an enclosing loop. This can lead to clearer Go code that is easier to maintain.

Example

Here we use the continue-keyword in a for-loop. Continue ends the current iteration of a loop, but then the next iteration begins as usual—the loop itself is not terminated.

Here When an element in the int slice equals 10, we use continue to stop processing of the current iteration.

package main

import "fmt"

func main() {
    elements := []int{10, 20}
    for i := range elements {
        // If element is 10, continue to next iteration.
        if elements[i] == 10 {
            fmt.Println("CONTINUE")
            continue
        }
        fmt.Println("ELEMENT:", elements[i])
    }
}CONTINUE
ELEMENT: 20

Label

We can use a named label to specify what enclosing loop we want to continue next. The current loop is exited, and the target loop has its next iteration.

Part 1 We have a named label called Outer to refer to the outer of the 2 loops in the program.

Part 2 When both loop iteration variables are equal to 1, we skip further iterations of the inner loop, and continue iterating the outer loop.

package main

import "fmt"

func main() {
    // Part 1: a named label outside of 2 nested for-loops.
    Outer:
    for i := range 3 {
        fmt.Println("--")
        for x := range 3 {
            fmt.Println(i, x)
            // Part 2: stop the inner loop and go to the next iteration of the outer loop.
            if i == 1 && x == 1 {
                continue Outer
            }
        }
    }
}--
0 0
0 1
0 2
--
1 0
1 1
--
2 0
2 1
2 2

Continue can be used to skip to the next iteration of the current loop. And with a label, it can continue to the next iteration of an enclosing loop.