Writing first Go program - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple Go program

What is the output of this Go program?

Go

package main
import "fmt"
func main() {
    fmt.Println("Hello, Go!")
}

A Hello Go!

B hello, go!

C hello Go

D Hello, Go!

💡 Hint

Look carefully at the exact string inside fmt.Println.

The program prints exactly what is inside the quotes, including capitalization and punctuation.

🧠 Conceptual

intermediate

Purpose of the main function in Go

What is the role of the main function in a Go program?

A It imports packages needed by the program.

B It defines global variables for the program.

C It is the starting point where the program begins execution.

D It handles errors during program execution.

💡 Hint

Think about where the computer starts running your code.

In Go, the main function is where the program starts running. Without it, the program has no entry point.

🔧 Debug

advanced

Identify the error in this Go program

What error will this Go program produce when run?

Go

package main
import "fmt"
func main() {
    fmt.Println("Welcome to Go")
    fmt.Println("Let's learn")
    fmt.Println("Go is fun")
}

A Runtime error: index out of range

B Syntax error: missing closing parenthesis

C Compilation error: undefined function

D No error, program runs fine

💡 Hint

Check the parentheses in the last fmt.Println line.

The last fmt.Println call is missing a closing parenthesis, causing a syntax error.

📝 Syntax

advanced

Correct way to import and use fmt package

Which option shows the correct way to import the fmt package and print "Go Rocks"?

A

import "fmt"
func main() { fmt.Println("Go Rocks") }

B

import fmt
func main() { fmt.Println("Go Rocks") }

C

import (fmt)
func main() { fmt.Println("Go Rocks") }

D

import fmt;
func main() { fmt.Println("Go Rocks") }

💡 Hint

Remember how Go imports packages with quotes.

Go imports packages using import "packageName" syntax. Parentheses are used for multiple imports.

🚀 Application

expert

Output of a Go program with variable and fmt.Printf

What is the output of this Go program?

Go

package main
import "fmt"
func main() {
    name := "Go Learner"
    age := 3
    fmt.Printf("%s is %d years old.\n", name, age)
}

A Go Learner is 3 years old.

B Go Learner 3 years old.

C %s is %d years old.

D Go Learner is years old 3.

💡 Hint

Look at how fmt.Printf formats strings with %s and %d.

fmt.Printf replaces %s with the string variable and %d with the integer variable in order.