Looping

The for statement is the only looping statement in Go. This requires that you specify three expressions, separated by ;:

• A short declaration or an assignment to an existing variable
• A condition to verify before each iteration
• An operation to execute at the end of the iteration

All of these statements can be optional, and the absence of a condition means that it is always true. A break statement interrupts the loop's execution, while continue skips the current iteration and proceeds with the next one:

for {                    // infinite loop
    if condition {
        break            // exit the loop
    }
}

for i < 0 {              // loop with condition
    if condition {
        continue         // skip current iteration and execute next    
    }
}

for i:=0; i < 10; i++ {  // loop with declaration, condition and operation 
}

When a combination of switch and for are nested, the continue and break statements refer to the inner flow control statement.

An outer loop or condition can be labelled using a name: expression, whereas the name is its identifier, and both loop and continue can be followed by the name in order to specify where to intervene, as shown in the following code:

label:
    for i := a; i<a+2; i++ {
        switch i%3 {
        case 0:
            fmt.Println("divisible by 3")
            break label                          // this break the outer for loop
        default:
            fmt.Println("not divisible by 3")
        }
    }