Output using fmt.Println in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the text "Hello, World!".

Go

package main

import "fmt"

func main() {
    fmt.[1]("Hello, World!")
}

Drag options to blanks, or click blank then click option'

APrint

BPrintline

CPrintf

DPrintln

Attempts:

3 left

💡 Hint

Common Mistakes

Using Print instead of Println, which does not add a new line.

Using Printline which does not exist.

The fmt.Println function prints the text followed by a new line.

2fill in blank

medium

Complete the code to print the value of variable name.

Go

package main

import "fmt"

func main() {
    name := "Alice"
    fmt.[1](name)
}

Drag options to blanks, or click blank then click option'

APrintln

BPrint

CPrintline

DPrintf

Attempts:

3 left

💡 Hint

Common Mistakes

Using Printf without format specifiers causes errors.

Using Printline which is not a valid function.

fmt.Println prints the value and adds a new line.

3fill in blank

hard

Fix the error in the code to print the number 10.

Go

package main

import "fmt"

func main() {
    num := 10
    fmt.[1](num)
}

Drag options to blanks, or click blank then click option'

APrintln

BPrintline

CPrint

DPrintf

Attempts:

3 left

💡 Hint

Common Mistakes

Using Printline which causes a compile error.

Using Print which prints without a new line.

fmt.Println correctly prints the number with a new line.

4fill in blank

hard

Fill both blanks to print the message and the number on separate lines.

Go

package main

import "fmt"

func main() {
    message := "Count"
    number := 5
    fmt.[1](message)
    fmt.[2](number)
}

Drag options to blanks, or click blank then click option'

APrintln

BPrint

CPrintf

DPrintline

Attempts:

3 left

💡 Hint

Common Mistakes

Using Printline which is not valid.

Using Println for both lines causing extra new lines.

Println prints with a new line, Print prints without a new line.

5fill in blank

hard

Fill all three blanks to print a formatted message with a variable.

Go

package main

import "fmt"

func main() {
    name := "Bob"
    fmt.[1]("Hello, %s!", [2])
    fmt.[3]("Goodbye!")
}

Drag options to blanks, or click blank then click option'

APrintln

Bname

CPrintf

DPrint

Attempts:

3 left

💡 Hint

Common Mistakes

Using Println instead of Printf for formatted strings.

Forgetting to pass the variable to Printf.

Printf prints formatted text, name is the variable, and Println prints with a new line.

Practice

1. What does the fmt.Println function do in Go?

easy

A. Creates a new package

B. Reads input from the user

C. Declares a new variable

D. Prints text or values to the screen with a new line

Solution

1. Step 1: Understand the purpose of fmt.Println

   The function fmt.Println is used to display output on the screen, automatically adding a new line after the output.

2. Step 2: Differentiate from other functions

   It does not read input, declare variables, or create packages; it only prints output.

3. Final Answer:

   Prints text or values to the screen with a new line -> Option D

4. Quick Check:

   fmt.Println prints output with newline [OK]

Hint: Remember: println means print with a new line [OK]

Common Mistakes:

• Confusing fmt.Println with input functions
• Thinking it declares variables
• Assuming it creates packages

2. Which of the following is the correct way to print "Hello, Go!" using fmt.Println?

easy

A. fmt.Println("Hello, Go!")

B. fmt.Println('Hello, Go!')

C. fmt.Println(Hello, Go!)

D. fmt.Println(Hello Go)

Solution

1. Step 1: Check string syntax in Go

   Strings must be enclosed in double quotes " ". Single quotes ' ' are for single characters.

2. Step 2: Validate the options

   fmt.Println("Hello, Go!") uses double quotes correctly. Options A, B, and C either use single quotes or no quotes, which causes errors.

3. Final Answer:

   fmt.Println("Hello, Go!") -> Option A

4. Quick Check:

   Strings need double quotes in fmt.Println [OK]

Hint: Use double quotes for strings in fmt.Println [OK]

Common Mistakes:

• Using single quotes for strings
• Omitting quotes around text
• Forgetting commas inside print

3. What will be the output of this Go code?

package main
import "fmt"
func main() {
    fmt.Println("Go", "is", "fun")
}

medium

A. Go is fun

B. Goisfun

C. "Go is fun"

D. Go, is, fun

Solution

1. Step 1: Understand fmt.Println with multiple arguments

   When multiple values are separated by commas, fmt.Println prints them separated by spaces automatically.

2. Step 2: Analyze the output

   The output will be the words separated by spaces: Go is fun, followed by a new line.

3. Final Answer:

   Go is fun -> Option A

4. Quick Check:

   fmt.Println adds spaces between arguments [OK]

Hint: Multiple arguments print with spaces automatically [OK]

Common Mistakes:

• Expecting no spaces between words
• Thinking commas print literally
• Confusing output with quotes

4. Find the error in this Go code snippet:

package main
import "fmt"
func main() {
    fmt.Println("Hello" + "World")
}

medium

A. Syntax error due to missing comma

B. Runtime error because + can't join strings

C. No error, it prints HelloWorld

D. fmt.Println requires parentheses

Solution

1. Step 1: Check string concatenation in Go

   Using + between strings concatenates them without spaces.

2. Step 2: Verify fmt.Println usage

   fmt.Println can print the concatenated string without error.

3. Final Answer:

   No error, it prints HelloWorld -> Option C

4. Quick Check:

   String + concatenates; fmt.Println prints result [OK]

Hint: String + joins text; no comma needed inside fmt.Println [OK]

Common Mistakes:

• Thinking + causes syntax error in print
• Expecting space between Hello and World
• Confusing + with comma separator

5. You want to print the numbers 1, 2, and 3 on the same line separated by spaces using fmt.Println. Which code snippet achieves this correctly?

hard

A. fmt.Println(1 2 3)

B. fmt.Println("1", "2", "3")

C. fmt.Println("1" "2" "3")

D. fmt.Println(1 + 2 + 3)

Solution

1. Step 1: Understand printing multiple values

   Using commas in fmt.Println prints each argument separated by spaces automatically.

2. Step 2: Analyze each option

   fmt.Println(1 2 3) causes syntax error (missing commas or operators).
   fmt.Println("1" "2" "3") concatenates adjacent strings to "123" without spaces.
   fmt.Println("1", "2", "3") prints 1 2 3 with spaces.
   fmt.Println(1 + 2 + 3) prints 6.

3. Step 3: Choose the best for printing numbers as strings separated by spaces

   fmt.Println("1", "2", "3") prints the numbers as strings separated by spaces, exactly as requested.

4. Final Answer:

   fmt.Println("1", "2", "3") -> Option B

5. Quick Check:

   Separate strings with commas to print spaced values [OK]

Hint: Use commas to separate values for spaced output [OK]

Common Mistakes:

• Using + to join numbers (adds them instead)
• Printing a single string instead of separate values
• Confusing string and integer printing