Why Go is widely used - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print "Hello, Go!".

Go

package main

import "fmt"

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

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

APrintfln

BPrint

CPrintf

DPrintln

Attempts:

3 left

💡 Hint

Common Mistakes

Using Print instead of Println which does not add a newline.

The Println function prints the text with a newline at the end.

2fill in blank

medium

Complete the code to declare a variable named 'count' of type int with value 10.

Go

package main

func main() {
    var count [1] = 10
}

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

Aint

Bstring

Cfloat64

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using string or float64 which are not integer types.

The variable count should be of type int to hold integer values.

3fill in blank

hard

Fix the error in the function signature to accept an integer parameter named 'n'.

Go

package main

func printNumber([1]) {
    // function body
}

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

Aint n

Bn: int

Cn int

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Using int n which is incorrect in Go.

In Go, function parameters are declared as name type, so n int is correct.

4fill in blank

hard

Fill both blanks to create a map from string to int with one key-value pair.

Go

package main

func main() {
    m := map[[1]][2]{
        "age": 30,
    }
}

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

Astring

Bint

Cfloat64

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using float64 or bool for keys or values which is incorrect here.

The map keys are strings and values are integers, so string and int are correct.

5fill in blank

hard

Fill all three blanks to create a slice of integers and append 5 to it.

Go

package main

import "fmt"

func main() {
    nums := [][1]{1, 2, 3}
    nums = append(nums, [2])
    fmt.[3](nums)
}

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

Aint

B5

CPrintln

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using string instead of int for the slice type.

Forgetting to append the correct value.

The slice holds integers, so int is correct. We append the number 5, and print with Println.

Practice

1. Why is Go considered easy to learn for new programmers?

easy

A. Because it requires writing a lot of code

B. Because it has a simple and clear syntax

C. Because it uses complex inheritance

D. Because it only runs on Windows

Solution

1. Step 1: Understand Go's syntax design

   Go was designed with simplicity in mind, making its syntax easy to read and write.

2. Step 2: Compare with other languages

   Unlike languages with complex features like inheritance, Go keeps things straightforward.

3. Final Answer:

   Because it has a simple and clear syntax -> Option B

4. Quick Check:

   Simplicity = A [OK]

Hint: Simple syntax means easy to learn [OK]

Common Mistakes:

• Thinking Go requires complex code
• Confusing Go with languages that have inheritance
• Believing Go only runs on Windows

2. Which of the following is the correct way to declare a variable in Go?

easy

A. declare x = 10

B. int x = 10

C. x := int 10

D. var x int = 10

Solution

1. Step 1: Recall Go variable declaration syntax

   In Go, variables can be declared using the 'var' keyword followed by the name, type, and value.

2. Step 2: Check each option

   var x int = 10 matches Go syntax. Options A, B, and C do not follow Go's rules.

3. Final Answer:

   var x int = 10 -> Option D

4. Quick Check:

   Go var declaration = D [OK]

Hint: Use 'var' keyword to declare variables in Go [OK]

Common Mistakes:

• Using C or Java style declarations
• Misplacing ':=' operator
• Using non-Go keywords like 'declare'

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

package main
import "fmt"
func main() {
    fmt.Println("Go runs fast")
}

medium

A. Go runs fast

B. fmt.Println("Go runs fast")

C. Go runs slow

D. Compilation error

Solution

1. Step 1: Understand the fmt.Println function

   fmt.Println prints the string inside quotes to the console.

2. Step 2: Check the string passed

   The string "Go runs fast" is printed exactly as is.

3. Final Answer:

   Go runs fast -> Option A

4. Quick Check:

   Print output = Go runs fast [OK]

Hint: fmt.Println prints the exact string [OK]

Common Mistakes:

• Confusing print with returning a string
• Expecting code to print the code itself
• Assuming compilation error without reason

4. Identify the error in this Go code snippet:

package main
import "fmt"
func main() {
    var count = 5
    if count > 3 {
        fmt.Println("Count is greater than 3")
    }
}

medium

A. No error, code runs correctly

B. Incorrect import statement

C. Missing semicolon after variable declaration

D. Missing parentheses in if condition

Solution

1. Step 1: Check variable declaration

   Variable 'count' is declared correctly with 'var count = 5'. No semicolon needed in Go.

2. Step 2: Check if statement syntax

   Go requires no parentheses around if condition, so 'if count > 3' is correct.

3. Final Answer:

   No error, code runs correctly -> Option A

4. Quick Check:

   Go syntax correct = C [OK]

Hint: Go if statements do not need parentheses [OK]

Common Mistakes:

• Adding semicolons unnecessarily
• Adding parentheses around if condition
• Thinking import fmt is wrong

5. Why is Go a popular choice for building cloud and web applications?

hard

A. Because it has slow execution but many libraries

B. Because it only works on desktop apps

C. Because it supports concurrency and fast performance

D. Because it requires manual memory management

Solution

1. Step 1: Understand Go's concurrency model

   Go has goroutines which allow many tasks to run at the same time efficiently.

2. Step 2: Consider performance and cloud needs

   Fast execution and easy concurrency make Go ideal for cloud and web apps that handle many users.

3. Final Answer:

   Because it supports concurrency and fast performance -> Option C

4. Quick Check:

   Concurrency + speed = B [OK]

Hint: Concurrency and speed make Go great for cloud apps [OK]

Common Mistakes:

• Thinking Go is slow
• Believing Go only works on desktop
• Confusing Go with languages needing manual memory management