Operators | Basic Coding Concepts

Operators are special symbols that tell the computer to perform specific operations. They're like the buttons on a calculator—each one does something different with your data.

Arithmetic Operators

These are your basic math operators. If you've used a calculator, you already know most of these!

Operator	Name	Example	Result
+	Addition	5 + 3	8
-	Subtraction	5 - 3	2
*	Multiplication	5 * 3	15
/	Division	10 / 4	2.5
%	Modulo (Remainder)	10 % 3	1
**	Exponentiation	2 ** 3	8

💡

The Modulo Operator (%)

The modulo operator gives you the remainder of a division. It's super useful for checking if a number is even (n % 2 === 0) or for wrapping around values (like hours on a clock).

Try It Yourself

String Concatenation

When you use + with strings, it joins them together. This is called concatenation.

let firstName = "John";
let lastName = "Doe";
let fullName = firstName + " " + lastName;
// Result: "John Doe"

// Modern way using template literals
let greeting = `Hello, ${firstName}!`;
// Result: "Hello, John!"

Comparison Operators

Comparison operators compare two values and return true or false.

Operator	Meaning	Example	Result
===	Equal to	5 === 5	true
!==	Not equal to	5 !== 3	true
>	Greater than	5 > 3	true
<	Less than	5 < 3	false
>=	Greater than or equal	5 >= 5	true
<=	Less than or equal	3 <= 5	true

⚠️

=== vs ==

Always use === (strict equality) instead of ==. The triple equals checks both value AND type, which prevents bugs. For example: 5 == "5" is true, but 5 === "5" is false.

Logical Operators

Logical operators let you combine multiple conditions:

AND

Both must be true

true && true = true

At least one must be true

true || false = true

NOT

Flips the value

!true = false

let age = 25;
let hasLicense = true;

// AND: both conditions must be true
let canDrive = age >= 16 && hasLicense;  // true

// OR: at least one condition must be true
let canEnter = age >= 21 || hasVIPPass;

// NOT: flips true to false (and vice versa)
let isMinor = !isAdult;  // If isAdult is true, isMinor is false

Assignment Operators

Besides the basic =, there are shorthand operators for common operations:

let score = 10;

score += 5;   // Same as: score = score + 5  → 15
score -= 3;   // Same as: score = score - 3  → 12
score *= 2;   // Same as: score = score * 2  → 24
score /= 4;   // Same as: score = score / 4  → 6

// Increment and Decrement
score++;      // Same as: score = score + 1  → 7
score--;      // Same as: score = score - 1  → 6

Quick Quiz

Key Takeaways

Arithmetic operators (+, -, *, /, %) do math
The + operator also joins strings together
Comparison operators (===, !==, >, <) return true/false
Logical operators (&&, ||, !) combine conditions
Shorthand operators like += make code cleaner

What's Next?

Now that you can work with data and operators, let's learn about conditionals— how to make your code choose different paths based on conditions!