🚀 Learning Go: Syntax, Variables, Loops, and Functions #1

I’ll share what I’m learning about Go (Golang) today. I'll cover the basics like syntax, variables, loops, and functions with examples. I'll keep it simple and to the point so you can easily follow along. Let's dive in!

---

🔎 1. Syntax in Go

Go is a statically typed, compiled language known for its simplicity and performance. Here’s a basic Go program structure:

package main

import "fmt"

func main() {
    fmt.Println("Hello, World!")
}

✅ Explanation:

• package main – Every Go program starts with a main package.

• import "fmt" – Imports the fmt package to print output.

• func main() – The main function is the entry point of the program.

• fmt.Println() – Prints text to the console.

---

🌟 2. Variables and Data Types in Go

In Go, variables are defined using the var keyword or the := shorthand.

✅ Declare and Assign Variables

var name string = "Chirag"
var age int = 25
var isActive bool = true

Or use shorthand:

name := "Chirag"
age := 25
isActive := true

✅ Data Types in Go

✅ Example of Different Types:

var score int = 90
var price float64 = 99.99
var available bool = true
var letter rune = 'G'
var initial byte = 65

---

🔁 3. Loops in Go

Loops help execute code repeatedly. Go mainly supports for loops.

✅ For Loop

Standard for loop:

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

---

✅ While-Style Loop

You can use for as a while loop:

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

---

✅ Infinite Loop

You can create an infinite loop using for without conditions:

for {
    fmt.Println("Running...")
    break // Use break to exit the loop
}

---

✅ Loop Over a String

You can loop over a string using range:

message := "Hello i am chirag"
for index, char := range message {
    fmt.Printf("Index: %d, Char: %c\n", index, char)
}

---

🏆 4. Functions in Go

Functions allow you to group reusable code.

✅ Basic Function

func greetUser() {
    fmt.Println("Hello, Chirag!")
}

Call it using:

// call it inside main function

greetUser()

// output would be
// Hello, Chirag!

---

✅ Function with Parameters and Return Value

func sum(a int, b int) int {
    return a + b
}

result := sum(10, 20)
fmt.Println("Sum is:", result)

// output is:
// Sum is: 30

---

✅ Multiple Parameters with the Same Type

Instead of writing a int, b int, c int, you can combine types:

func sumThree(a, b, c int) int {
    return a + b + c
}

sumThree(10, 20, 30)
// output is:
// 60

---

✅ Named Return Value

You can define a named return value directly:

func subtract(a int, b int) (result int) {
    result = a - b
    return
}
subtract(10, 5)
// output is:
5

---

⚠️ 5. Error Handling in Go

Go handles errors using the error type.

✅ Function with Error Handling

func divide(a float32, b float32) (float32, error) {
    if b == 0 {
        return 0, fmt.Errorf("cannot divide by zero")
    }
    return a / b, nil
}
divide(10,0)
divide(10,5)

// output is :
// 1. cannot divide by zero
// 2. 2.0
// it will return float data type value having decimal number

✅ Use it Like This:

result, err := divide(10, 0)
if err != nil {
    fmt.Println("Error:", err)
} else {
    fmt.Println("Result:", result)
}
// and you can either user _ or catch in another variable 
// but golang , restrict it , to use your declare variable what you hace declared

---

🎯 6. Use of _ in Golang

The underscore _ is used to ignore values you don’t want to use.

✅ Example:

If a function returns two values and you only need one:

result, _ := divide(10, 2)
fmt.Println("Result:", result)

In this example, the second return value (error) is ignored using _.

---

🚀 Complete Example

Here's a complete example combining functions, error handling, and loops:

package main

import "fmt"

func greetUser() {
    fmt.Println("Welcome to Go!")
}

func sum(a, b int) int {
    return a + b
}

func divide(a, b float32) (float32, error) {
    if b == 0 {
        return 0, fmt.Errorf("cannot divide by zero")
    }
    return a / b, nil
}

func main() {
    greetUser()

    result := sum(10, 20)
    fmt.Println("Sum is:", result)

    quotient, err := divide(100, 0)
    if err != nil {
        fmt.Println("Error:", err)
    } else {
        fmt.Println("Quotient is:", quotient)
    }

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

    message := "Hello"
    for _, char := range message {
        fmt.Printf("Char: %c\n", char)
    }
}

---

🔮 What’s Coming Next

Next week, I’ll cover:

✅ if-else, else and switch cases
✅ array , slices
✅ Struct, Maps, and Pointers

Stay tuned for more! 🚀 and do follow me