Arithmetic operators in Javascript

Introduction

Arithmetic operators help you do math with numbers in your program. They let you add, subtract, multiply, and divide values easily.

Calculating the total price of items in a shopping cart.

Finding the difference between two dates or times.

Increasing a score in a game after a player earns points.

Splitting a bill evenly among friends.

Converting units, like inches to centimeters.

Syntax

Javascript

result = value1 + value2;  // addition
result = value1 - value2;  // subtraction
result = value1 * value2;  // multiplication
result = value1 / value2;  // division
result = value1 % value2;  // remainder (modulus)
result = value1 ** value2; // exponentiation (power)

Use + for adding numbers or joining text (strings).

The % operator gives the remainder after division.

Examples

Adds 5 and 3 to get 8.

Javascript

let sum = 5 + 3;  // sum is 8

Subtracts 4 from 10 to get 6.

Javascript

let difference = 10 - 4;  // difference is 6

Multiplies 7 by 2 to get 14.

Javascript

let product = 7 * 2;  // product is 14

Divides 10 by 3 and gives the remainder 1.

Javascript

let remainder = 10 % 3;  // remainder is 1

Sample Program

This program shows how to use each arithmetic operator with two numbers, 12 and 5. It prints the result of each operation.

Javascript

const a = 12;
const b = 5;

console.log(`Addition: ${a} + ${b} = ${a + b}`);
console.log(`Subtraction: ${a} - ${b} = ${a - b}`);
console.log(`Multiplication: ${a} * ${b} = ${a * b}`);
console.log(`Division: ${a} / ${b} = ${a / b}`);
console.log(`Remainder: ${a} % ${b} = ${a % b}`);
console.log(`Exponentiation: ${a} ** 2 = ${a ** 2}`);

Important Notes

Division / can give decimal numbers if the division is not exact.

Exponentiation ** raises a number to the power of another number.

Remember that + can also join text, so be careful when mixing numbers and strings.

Summary

Arithmetic operators let you do basic math in your code.

Use +, -, *, /, %, and ** for addition, subtraction, multiplication, division, remainder, and power.

They help solve many everyday problems like calculating totals or splitting amounts.

Practice

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

easy

A. %

B. /

C. **

D. *

Solution

1. Step 1: Understand the remainder operator

   The operator % returns the remainder after division of two numbers.

2. Step 2: Compare with other operators

   / is division, ** is power, and * is multiplication, so they don't give remainder.

3. Final Answer:

   % -> Option A

4. Quick Check:

   Remainder operator = % [OK]

Hint: Remainder operator looks like a percent sign % [OK]

Common Mistakes:

• Confusing division / with remainder %
• Using * or ** instead of %
• Thinking + or - can give remainder

2. Which of the following is the correct syntax to calculate 5 to the power of 3 in JavaScript?

easy

A. 5 ** 3

B. 5 ^^ 3

C. 5 ^ 3

D. pow(5, 3)

Solution

1. Step 1: Identify the power operator in JavaScript

   JavaScript uses ** to calculate powers, like 5 ** 3 means 5 to the power 3.

2. Step 2: Check other options for correctness

   ^ is bitwise XOR, ^^ is invalid syntax, and pow() is not a built-in function in JavaScript.

3. Final Answer:

   5 ** 3 -> Option A

4. Quick Check:

   Power operator = ** [OK]

Hint: Use ** for power, not ^ or pow() [OK]

Common Mistakes:

• Using ^ instead of ** for power
• Trying to use pow() like in other languages
• Typing invalid operators like ^^

3. What will be the output of the following code?

console.log(10 % 4);

medium

A. 6

B. 0

C. 2

D. 4

Solution

1. Step 1: Calculate 10 divided by 4

   10 divided by 4 is 2 with a remainder of 2.

2. Step 2: Understand the % operator

   The % operator returns the remainder, so 10 % 4 equals 2.

3. Final Answer:

   2 -> Option C

4. Quick Check:

   10 % 4 = 2 [OK]

Hint: Remainder is what's left after division [OK]

Common Mistakes:

• Confusing remainder with quotient
• Thinking % does division
• Choosing 0 or 4 as remainder incorrectly

4. Find the error in this code snippet:

let result = 5 **;
console.log(result);

medium

A. console.log syntax error

B. Using wrong operator for power

C. Variable name 'result' is invalid

D. Missing right operand for ** operator

Solution

1. Step 1: Check the power operator usage

   The power operator ** needs two operands, like 5 ** 2. Here, the right operand is missing.

2. Step 2: Verify other parts of the code

   The variable name and console.log syntax are correct, so no errors there.

3. Final Answer:

   Missing right operand for ** operator -> Option D

4. Quick Check:

   Power operator needs two numbers [OK]

Hint: Power operator needs number on both sides [OK]

Common Mistakes:

• Leaving out the second number after **
• Thinking variable names cause error here
• Assuming console.log is wrong

5. You want to split 100 candies equally among 6 kids and find how many candies remain undistributed. Which expression gives the number of leftover candies?

hard

A. 100 / 6

B. 100 % 6

C. 100 - 6

D. 100 ** 6

Solution

1. Step 1: Understand the problem

   We want the leftover candies after dividing 100 by 6, which means the remainder.

2. Step 2: Choose the correct operator

   The remainder operator % gives the leftover amount, so 100 % 6 is correct.

3. Final Answer:

   100 % 6 -> Option B

4. Quick Check:

   Leftover = total % number [OK]

Hint: Use % to find leftovers after division [OK]

Common Mistakes:

• Using / which gives quotient, not remainder
• Subtracting numbers directly instead of remainder
• Using power operator mistakenly