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.