Constants

• Math.PI → 3.141592653589793
• Math.E → 2.718281828459045
• Math.LN2 → 0.6931471805599453 (Natural log of 2)
• Math.SQRT2 → 1.4142135623730951 (Square root of 2)

Rounding & Truncation

• Math.floor(x) → Rounds down to the nearest integer.
• Math.ceil(x) → Rounds up to the nearest integer.
• Math.round(x) → Rounds to the nearest integer (>= 0.5 rounds up).
• Math.trunc(x) → Removes the decimal part (no rounding).

console.log(Math.floor(4.9)); // 4
console.log(Math.ceil(4.1)); // 5
console.log(Math.round(4.5)); // 5
console.log(Math.trunc(-4.9)); // -4

Random Number Generation

• Math.random() → Returns a random decimal between 0 and 1 (excluding 1).
• Get a random integer in range [min, max]:

function getRandomInt(min: number, max: number) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}
console.log(getRandomInt(1, 10)); // e.g. 7

Min & Max

• Math.max(...values) → Returns the largest value.
• Math.min(...values) → Returns the smallest value.

let numbers = [3, 7, 2, 9, 5];
console.log(Math.max(...numbers)); // 9
console.log(Math.min(...numbers)); // 2

Power & Roots