Arithmetic operators in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are arithmetic operators in Go?

Arithmetic operators are symbols used to perform basic math operations like addition (+), subtraction (-), multiplication (*), division (/), and modulus (%).

beginner

What does the % operator do in Go?

The % operator gives the remainder after dividing two integers. For example, 7 % 3 equals 1 because 7 divided by 3 leaves a remainder of 1.

intermediate

How do you perform division with floating-point numbers in Go?

To divide floating-point numbers, use variables of type float32 or float64. For example, 5.0 / 2.0 equals 2.5.

intermediate

What happens if you divide by zero in Go?

Dividing by zero causes a runtime panic in Go. You should always check the divisor before dividing to avoid this error.

beginner

Write a Go expression to add two variables a and b.

The expression is: a + b

Which operator is used for multiplication in Go?

A -

B *

C +

D /

The * symbol is used for multiplication.

What is the result of 10 % 4 in Go?

A 2

B 0

C 4

D 6

10 divided by 4 leaves a remainder of 2, so 10 % 4 equals 2.

What type should variables be to get a decimal result when dividing in Go?

A bool

B string

C int

D float32 or float64

Only float32 or float64 types can hold decimal numbers for division results.

What happens if you divide an integer by zero in Go?

A Returns zero

B Returns infinity

C Causes a runtime error (panic)

D Returns NaN

Dividing by zero causes a runtime panic error in Go.

Which operator subtracts one number from another in Go?

A -

B *

C +

D /

The - operator subtracts numbers.

Explain the use of arithmetic operators in Go with examples.

Think about how you do basic math with numbers in Go code.

What precautions should you take when using division in Go?

Consider what happens if the divisor is zero or if you want decimal results.

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