Go: Control Flow

Go: Control Flow

What are control flow statements in Go?

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Elucian Moise
·

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Control flow statements in Go programming language are statements that control the flow of execution of the program. They allow you to specify the order in which statements are executed.

Syntax Examples

Following are the control flow statements in Go:

if statement:

The if statement allows you to execute a block of code if a specified condition is true.

if a > b {
    fmt.Println("a is greater than b")
}

if-else statement:

The if-else statement allows you to execute a block of code if a specified condition is true and another block of code if the condition is false.

if a > b {
    fmt.Println("a is greater than b")
} else {
    fmt.Println("b is greater than a")
}

else-if statement:

The else-if statement allows you to check multiple conditions in a single if statement.

if a > b {
    fmt.Println("a is greater than b")
} else if a < b {
    fmt.Println("b is greater than a")
} else {
    fmt.Println("a and b are equal")
}

switch statement:

The switch statement allows you to select one of many blocks of code to execute based on a specified value.

switch day {
    case "Monday":
        fmt.Println("Today is Monday")
    case "Tuesday":
        fmt.Println("Today is Tuesday")
    case "Wednesday":
        fmt.Println("Today is Wednesday")
    default:
        fmt.Println("Unknown day")
}

for loop statement:

The for loop allows you to execute a block of code multiple times based on a specified condition.

for i := 0; i < 5; i++ {
    fmt.Println(i)
}

range loop statement:

The range loop allows you to iterate over elements of an array, slice, map, string, or channel.

numbers := []int{1, 2, 3, 4, 5}
for index, value := range numbers {
    fmt.Printf("Index: %d Value: %d\n", index, value)
}

break statement:

The break statement allows you to terminate a loop or switch statement prematurely.

for i := 0; i < 5; i++ {
    if i == 3 {
        break
    }
    fmt.Println(i)
}

continue statement:

The continue statement allows you to skip the current iteration of a loop and continue with the next iteration.

for i := 0; i < 5; i++ {
    if i == 3 {
        continue
    }
    fmt.Println(i)
}

These control flow statements can be used to create complex and flexible programs in Go by controlling the order in which different statements are executed.

Using loops

Here are some examples of loop statements used with collections in Go:

  • Using for loop to iterate over an array:
numbers := [5]int{1, 2, 3, 4, 5}
for i := 0; i < len(numbers); i++ {
    fmt.Print(numbers[i], " ")
}
// Output: 1 2 3 4 5
  • Using for range loop to iterate over an array:
numbers := [5]int{1, 2, 3, 4, 5}
for index, value := range numbers {
    fmt.Printf("Index: %d Value: %d\n", index, value)
}
// Output:
// Index: 0 Value: 1
// Index: 1 Value: 2
// Index: 2 Value: 3
// Index: 3 Value: 4
// Index: 4 Value: 5
  • Using for range loop to iterate over a slice:
numbers := []int{1, 2, 3, 4, 5}
for index, value := range numbers {
    fmt.Printf("Index: %d Value: %d\n", index, value)
}
// Output:
// Index: 0 Value: 1
// Index: 1 Value: 2
// Index: 2 Value: 3
// Index: 3 Value: 4
// Index: 4 Value: 5
  • Using for range loop to iterate over a map:
ages := map[string]int{
    "Alice": 25,
    "Bob":   30,
    "Carol": 35,
}
for name, age := range ages {
    fmt.Printf("%s is %d years old\n", name, age)
}
// Output:
// Alice is 25 years old
// Bob is 30 years old
// Carol is 35 years old
  • Using for loop to iterate over a slice and break statement to exit once a condition is met:
numbers := []int{1, 2, 3, 4, 5}
for _, value := range numbers {
    if value > 3 {
        break
    }
    fmt.Print(value, " ")
}
// Output: 1 2 3
  • Using for loop to iterate over a slice and continue statement to skip an iteration based on a condition:
numbers := []int{1, 2, 3, 4, 5}
for _, value := range numbers {
    if value%2 == 0 {
        continue
    }
    fmt.Print(value, " ")
}
// Output: 1 3 5

2D Slice Loop

Here's an example of a 2D slice with nested loops in Go:

package main

import "fmt"

func main() {
    // Create a 2D slice with 3 rows and 4 columns
    numbers := [][]int{
        {1, 2, 3, 4},
        {5, 6, 7, 8},
        {9, 10, 11, 12},
    }

    // Use nested loops to iterate over the 2D slice and print each element
    for i := 0; i < len(numbers); i++ {
        for j := 0; j < len(numbers[i]); j++ {
            fmt.Print(numbers[i][j], " ")
        }
        fmt.Println()
    }
}

This code creates a 2D slice with 3 rows and 4 columns, then uses nested loops to iterate over the slice and print each element. The outer loop iterates over each row, and the inner loop iterates over each column in the current row. The fmt.Println() statement is used to move to the next line after printing each row so that the output is properly formatted.

Disclaim. This entire article was generated by AI. I have nothing to add. You are welcome to ask other question yourself and generate more examples. If you find dis insufficient, visit my website text article and learn more: https://sagecode.net/go/control.html

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