Arithmetic operators in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add two numbers and print the result.

Go

package main

import "fmt"

func main() {
    sum := 5 [1] 3
    fmt.Println(sum)
}

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

A-

B+

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication instead of addition.

The + operator adds two numbers together.

2fill in blank

medium

Complete the code to find the remainder when 10 is divided by 3.

Go

package main

import "fmt"

func main() {
    remainder := 10 [1] 3
    fmt.Println(remainder)
}

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

A%

B+

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using division instead of modulus.

The % operator gives the remainder of division.

3fill in blank

hard

Fix the error in the code to multiply two numbers correctly.

Go

package main

import "fmt"

func main() {
    product := 4 [1] 5
    fmt.Println(product)
}

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

A*

B-

C+

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition or division instead of multiplication.

The * operator multiplies two numbers.

4fill in blank

hard

Fill both blanks to create a map of words to their lengths for words longer than 3 characters.

Go

package main

import "fmt"

func main() {
    words := []string{"go", "code", "fun", "learn"}
    lengths := map[string]int{}
    for _, word := range words {
        if len(word) [1] 3 {
            lengths[word] = [2]
        }
    }
    fmt.Println(lengths)
}

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

A>

Bword

Clen(word)

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' for length comparison.

Assigning the word instead of its length.

The condition len(word) > 3 checks word length. The value len(word) stores the length.

5fill in blank

hard

Fill all three blanks to create a map with uppercase keys and values greater than 2.

Go

package main

import (
    "fmt"
    "strings"
)

func main() {
    data := map[string]int{"go": 1, "code": 4, "fun": 3}
    result := map[string]int{}
    for k, v := range data {
        if v [3] 2 {
            result[[1]] = [2]
        }
    }
    fmt.Println(result)
}

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

Astrings.ToUpper(k)

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using the key instead of uppercase key.

Using '<' instead of '>' in condition.

We check if v > 2. Then store the value v with the uppercase key strings.ToUpper(k).

Practice

1. Which arithmetic operator in Go is used to find the remainder of a division?

easy

A. /

B. +

C. *

D. %

Solution

1. Step 1: Understand the remainder operation

   The remainder operator returns what is left after division.

2. Step 2: Identify the correct operator in Go

   In Go, the remainder operator is represented by the percent sign '%'.

3. Final Answer:

   % -> Option D

4. Quick Check:

   Remainder = % [OK]

Hint: Remainder uses % like in many languages [OK]

Common Mistakes:

• Confusing division / with remainder %
• Using * for remainder
• Using + for remainder

2. Which of the following is the correct way to write a multiplication operation in Go?

easy

A. a x b

B. a . b

C. a * b

D. a & b

Solution

1. Step 1: Recall Go's multiplication syntax

   Go uses the asterisk '*' symbol for multiplication.

2. Step 2: Check each option

   Only 'a * b' uses the correct multiplication operator.

3. Final Answer:

   a * b -> Option C

4. Quick Check:

   Multiplication = * [OK]

Hint: Use * for multiplication, not x or & [OK]

Common Mistakes:

• Using 'x' instead of '*'
• Using '.' or '&' for multiplication
• Confusing syntax with other languages

3. What is the output of this Go code?

package main
import "fmt"
func main() {
  a := 7
  b := 3
  fmt.Println(a / b)
}

medium

A. 2.3333333

B. 2

C. 3

D. 0

Solution

1. Step 1: Identify variable types and operation

   Both a and b are integers, so division is integer division.

2. Step 2: Calculate integer division result

   7 divided by 3 is 2.333..., but integer division drops decimals, so result is 2.

3. Final Answer:

   2 -> Option B

4. Quick Check:

   Integer division 7/3 = 2 [OK]

Hint: Integer division drops decimals, result is int [OK]

Common Mistakes:

• Expecting float result
• Confusing integer division with float division
• Using wrong operator

4. Find the error in this Go code snippet:

package main
import "fmt"
func main() {
  x := 10
  y := 0
  fmt.Println(x / y)
}

medium

A. Division by zero causes runtime panic

B. Syntax error: missing semicolon

C. Variable y is not declared

D. No error, prints 0

Solution

1. Step 1: Analyze the division operation

   The code divides x by y, where y is zero.

2. Step 2: Understand Go's behavior on division by zero

   Dividing by zero causes a runtime panic (error) in Go.

3. Final Answer:

   Division by zero causes runtime panic -> Option A

4. Quick Check:

   Division by zero = runtime panic [OK]

Hint: Never divide by zero; it crashes the program [OK]

Common Mistakes:

• Thinking it prints 0
• Expecting compile-time error
• Ignoring runtime panic

5. Given the Go code below, what is the output?

package main
import "fmt"
func main() {
  a := 15
  b := 4
  c := a % b
  d := a / b
  fmt.Println(c + d)
}

hard

A. 6

B. 3

C. 19

D. 4

Solution

1. Step 1: Calculate remainder c = a % b

   15 % 4 equals 3 because 4*3=12 and 15-12=3.

2. Step 2: Calculate integer division d = a / b

   15 / 4 equals 3 because integer division drops decimals.

3. Step 3: Add c + d

   3 + 3 equals 6.

4. Final Answer:

   6 -> Option A

5. Quick Check:

   15 % 4 = 3, 15 / 4 = 3, 3 + 3 = 6 [OK]

Hint: Add remainder and integer division results carefully [OK]

Common Mistakes:

• Miscomputing remainder
• Using float division instead of integer
• Adding wrong values