All math arguments must be finite numbers, and math functions may return only finite numbers. sqrt rejects negative inputs. pow accepts negative bases and exponents when their result is finite and rejects infinite results.

random(min, max) requires min < max; equal or reversed bounds are errors. Before seeding, it uses ambient randomness. randomSeed(seed) converts the seed to an unsigned 32-bit integer and starts the p5.js-compatible 32-bit linear congruential sequence. Reseeding restarts that sequence, and random state belongs to one program run. Generated values are minimum-inclusive and maximum-exclusive.

Note: Trigonometric functions use degrees, not radians. This is more intuitive for beginners and matches the arc function. Since there are many examples in other languages using radians, we have conversion functions radians(degrees) and degrees(radians).

random(min, max)

Random float between min (inclusive) and max (exclusive).

let value = random(0, 1);
print(value);

randomSeed(n)

Set random seed for reproducible outputs. This will make sure you get the same sequence of random numbers every time you run your program.

randomSeed(42);
let value = random(0, 1);
print(value);

floor(n)

Round down to integer.

let value = floor(3.7);
print(value); // should print 3

ceil(n)

Round up to integer

let value = ceil(3.7);
print(value); // should print 4

round(n)

Round to nearest integer.

let value = round(3.7);
print(value); // should print 4
value = round(3.4);
print(value); // should print 3

abs(n)

Absolute value

let value = abs(-3);
print(value); // should print 3

min(a, b)

Smaller of two values

let value = min(3, 5);
print(value); // should print 3

max(a, b)

Larger of two values

let value = max(3, 5);
print(value); // should print 5

sin(degrees)

Sine (input in degrees)

repeat(degrees,0,360, 45) {
	let value = sin(degrees);
	print(value);
}

Sine cosine functions are great for describing arcs and circles. This uses polar coordinates to draw a circle.

strokeWidth(5);
repeat(degrees, 0, 360, 12) {
	let x = sin(degrees) * 25 + WIDTH / 2;
	let y = cos(degrees) * 25 + HEIGHT / 2;
	point(x, y);
}

cos(degrees)

Cosine (input in degrees)

let degrees = 180;
let value = cos(degrees);
print(value);

radians(degrees)

Convert degrees to radians.

let angle = 180;
let value = radians(angle);
if(value == PI) {
	print("value is PI! Yay!");
}

degrees(radians)

Convert radians to degrees.

let value = degrees(PI);
print(value); // should print 180

sqrt(n)

Square root

pow(base, exp)

Exponentiation