Operators

1 min read | JavaScript Tutorial

🎓

Doing SIWES / IT attachment?

Get a structured training programme, a supervised digital logbook, and a completion certificate with LabsICT SIWES / IT.

Explore SIWES / IT Training

JavaScript Operators

Operators are the building blocks of expressions. They let you perform arithmetic, assign values, compare data, and combine logic. Mastering operators is like learning the vocabulary of the language.

Arithmetic Operators

console.log(10 + 5);
console.log(10 - 5);
console.log(10 * 5);
console.log(10 / 3);
console.log(10 % 3);
console.log(2 ** 3);

Assignment Operators

let x = 10;
x += 5;
console.log(x);
x *= 2;
console.log(x);
x %= 7;
console.log(x);

Increment and Decrement

let count = 0;
count++;
console.log(count);
count--;
console.log(count);

String Operators

let first = "Hello";
let second = "World";
console.log(first + " " + second);
let greeting = "Hi";
greeting += " there!";
console.log(greeting);

Logical Operators

console.log(true && false);
console.log(true || false);
console.log(!true);

Nullish Coalescing Operator

let name = null;
console.log(name ?? "Guest");
let age = 0;
console.log(age ?? 25);

Optional Chaining

const user = { profile: { name: "Alice" } };
console.log(user?.profile?.name);
console.log(user?.address?.city);

Falsy Values

console.log(Boolean(false));
console.log(Boolean(0));
console.log(Boolean(""));
console.log(Boolean(null));
console.log(Boolean(undefined));
console.log(Boolean(NaN));

These six values are falsy. Everything else is truthy.

Concepts Explained