Arithmetic & Assignment in JavaScript
From the JavaScript cheat sheet · Operators · verified Jul 2026
Arithmetic & Assignment
Math and assignment operators
javascript
// Arithmetic
let x = 10 + 5; // 15
x = 10 - 5; // 5
x = 10 * 5; // 50
x = 10 / 5; // 2
x = 10 % 3; // 1 (remainder)
x = 2 ** 3; // 8 (exponentiation)
// Assignment operators
x += 5; // x = x + 5
x -= 5; // x = x - 5
x *= 5; // x = x * 5
x /= 5; // x = x / 5
x %= 3; // x = x % 3
x **= 2; // x = x ** 2
// Increment/Decrement
x++; // post-increment
++x; // pre-increment
x--; // post-decrement
--x; // pre-decrement💡 + operator concatenates strings but performs addition with numbers
⚡ Pre-increment (++x) returns new value, post-increment (x++) returns old
📌 Use ** for exponentiation instead of Math.pow()
🔥 Assignment operators provide shorthand for common operations