If-Else Statement in Go

In this tutorial, we will learn about if-else statements in Go. We will cover the basics of conditional execution using if-else statements.

What is an If-Else statement

An if-else statement is a conditional statement that executes one block of code if a specified condition is true, and another block of code if the condition is false.

Syntax

The syntax for the if-else statement in Go is:

if condition {
    // Code block to execute if condition is true
} else {
    // Code block to execute if condition is false
}

The if-else statement evaluates the specified condition. If the condition is true, the code block inside the if statement is executed; otherwise, the code block inside the else statement is executed.

Flowchart of If Else Statement

Example 1: Checking if a Number is Even or Odd

  1. Declare an integer variable num.
  2. Assign a value to num.
  3. Use an if-else statement to check if num is even or odd.
  4. Print a message indicating whether num is even or odd.

Go Program

package main
import "fmt"
func main() {
    num := 10
    if num % 2 == 0 {
        fmt.Printf("%d is even.", num)
    } else {
        fmt.Printf("%d is odd.", num)
    }
}

Output

10 is even.

Example 2: Checking if a String Starts with a Specific Value

  1. Declare a string variable str.
  2. Assign a value to str.
  3. Use an if-else statement to check if str starts with a specific value.
  4. Print a message indicating the result of the check.

Go Program

package main
import "fmt"
func main() {
    str := "Hello, world!"
    if str[:5] == "Hello" {
        fmt.Println("String starts with 'Hello'.")
    } else {
        fmt.Println("String does not start with 'Hello'.")
    }
}

Output

String starts with 'Hello'.

Example 3: Checking if a Number is Positive or Negative

  1. Declare an integer variable num.
  2. Assign a value to num.
  3. Use an if-else statement to check if num is positive or negative.
  4. Print a message indicating whether num is positive or negative.

Go Program

package main
import "fmt"
func main() {
    num := -5
    if num > 0 {
        fmt.Printf("%d is positive.", num)
    } else {
        fmt.Printf("%d is negative or zero.", num)
    }
}

Output

-5 is negative or zero.