Control Flow in Go - Making Decisions and Loops Easy

Welcome back to the “Go Deep with Golang” series.

In the previous blogs, we covered the basics of Go, including variables, constants, and data types.

Now, it's time to explore one of the most important aspects of any programming language.

Control Flow

Control flow determines how your program makes decisions and repeats tasks. It helps decide what runs, when it runs, and how often it runs.

Let's explore all the control structures with their code snippets.

Conditional Statements in Go

The if statement

poackage main
import 'fmt'

func main() {
   num := 10
   if num > 0 {
     fmt.Println("Positive number")
   }
}

Short Statement in if

Go allows variable initialization directly inside if.

if num:= 10; num %2 == 0 {
    fmt.Println("Even number")
} else {
    fmt.Println("Odd numner")
}

The variable number is scoped only inside this if block.

Loops in GO

Go has only one loop, the for loop, but it's extremely flexible. You can use it as a traditional loop, a while-loop, or even create infinite loops.

Traditional for Loop

for i := 1; i <= 5; i++ {
  fmt.Println(i)
}

Structure of this for loop code

• initialisation → i := 1

• Condition → i <= 5

• Post statement → i++

While-like for Loop

You can skip initialisation and post expression.

i := 1
for i <= 5 {
    fmt.Println(i)
    i++
}

Infinite Loop

Omit all parts of for to create an infinite loop

for {
   fmt.Println("Running..")
   break
}

Switch Statement

day := 3
switch day {
case 1:
    fmt.Println("Monday")
case 2:
    fmt.Println("Tuesday")
case 3:
    fmt.Println("Wednesday")
default:
    fmt.Println("Invalid day")
}

Unique Features of switch in Go

• No break needed - Go automatically breaks after each case.

• Multiple values per case:

  •   day :=3
      switch day {
          case 1,2,3,4,5:
            fmt.Println("Weekday")
          case 6,7:
            fmt.Println("Weekend")
      }
    

• Expressionless switch - act like a chain of if-else:

    num := 42
    switch {
    case num < 0:
        fmt.Println("Negative")
    case num == 0:
        fmt.Println("Zero")
    default:
        fmt.Println("Positive")
    }
  

• fallthrough keyword - forces the execution of the next case:

    switch num := 2; num {
    case 1:
        fmt.Println("One")
    case 2:
        fmt.Println("Two")
        fallthrough
    case 3:
        fmt.Println("Three")
    default:
        fmt.Println("Other")
    }
  
    // Output
    Two
    Three
  

Goto Statement

This allows you to jump to a labeled statement. It’s rarely used but can help in breaking out of nested loops.

for i := 1; i <= 3; i++ {
    for j := 1; j <= 3; j++ {
        if i*j > 3 {
            goto end
        }
        fmt.Println(i, j)
    }
}
end:
fmt.Println("Loop ended")

// output
1 1
1 2
Loop ended

Conclusion

Control flow in Go is designed to be simple, readable, and minimalistic, yet powerful enough to handle all logical branching and looping needs. With just a few keywords—if, for, and switch—Go provides all the flexibility most programs need.

Understanding these concepts builds a strong foundation for writing clean, predictable, and efficient Go code.