break Statement

A break statement exits the nearest enclosing for, switch or select statement. It is useful when further work is unnecessary.

Inside a search loop, you can break as soon as a match appears. Execution then resumes with the first statement after that loop. break does not terminate the entire program.

In nested loops, an unlabeled break stops only the innermost applicable construct. Go also supports labeled breaks when a controlled exit from an outer construct is required.

Follow this diagram before executing the example. Check where a value or decision changes what runs next.

This example is a complete program. Save it as main.go or paste it into the Go Playground.

Go code

package main

import "fmt"

func main() {
	numbers := []int{3, 6, 9, 12}
	for _, number := range numbers {
		if number == 9 {
			fmt.Println("Found 9")
			break
		}
		fmt.Println("Checked", number)
	}
	fmt.Println("Search finished")
}

Output

Checked 3
Checked 6
Found 9
Search finished

The loop checks 3 and 6. When it reaches 9, the condition is true, the program prints Found 9 and breaks. It never examines 12; execution continues with Search finished.

• break stops a loop; it does not return from the surrounding function.
• Inside nested loops, remember which loop the unlabeled break affects.

Change the target to 12. Explain why one more Checked line appears before the match.

Tip: Edit the example above, predict the output, and run the modified code to test your reasoning.

You have practiced Go break Statement in a small, self-contained program. The important habit is to predict what runs, inspect the actual output and distinguish the language rule from the particular example.

Before continuing, make sure you can explain the program to someone who has not seen it, including the line that changes its result.