The dart:math Library

Dart comes with several built-in libraries that you can leverage to implement various features, including a dedicated library for mathematical operations.

import 'dart:math';Code language: JavaScript (javascript)

Common Constants

print(pi);      // 3.141592653589793 Pi
print(e);       // 2.718281828459045 Euler's number
print(sqrt2);   // √2 ≈1.4142Code language: PHP (php)

Trigonometric Functions

sin() cos() tan() Parameters: radians. Degrees ↔ Radians conversion: radians = degrees × pi / 180

void trigDemo() {
  assert(cos(pi) == -1.0);

  int degrees = 30;
  double radians = degrees * pi / 180;
  double result = sin(radians);
  // Never compare floating-point numbers directly with ==, check absolute difference
  assert((result - 0.5).abs() < 0.01);
}Code language: Dart (dart)

Maximum / Minimum Values

assert(max(1, 1000) == 1000);
assert(min(1, -1000) == -1000);

Random Numbers with Random

void randomDemo() {
  final rand = Random();
  double d = rand.nextDouble();   // [0.0, 1.0)
  int i = rand.nextInt(10);       // 0 ~ 9
  bool b = rand.nextBool();       // true / false

  // Cryptographically secure random for passwords and keys
  final secureRand = Random.secure();
}Code language: Dart (dart)

Frequently Used Functions

sqrt(9);      // Square root, returns 3.0
pow(2, 3);    // Exponentiation 2^3=8.0
log(e);       // Natural logarithm
atan2(y, x);  // Arctangent, widely used to calculate angles in coordinate systemsCode language: Dart (dart)

Full Example

import 'dart:math';

void main() {
  // Constants
  print('pi = $pi');
  print('e = $e');

  // Trigonometric functions
  final rad30 = 30 * pi / 180;
  print('sin30° = ${sin(rad30)}');

  // max min
  print('max(2,9) = ${max(2,9)}');
  print('min(2,9) = ${min(2,9)}');

  // Random values
  final r = Random();
  print('Random integer 0~9：${r.nextInt(10)}');
  print('[0,1) floating point：${r.nextDouble()}');
  print('Random boolean：${r.nextBool()}');
}Code language: Dart (dart)

Run the Example

D:\dartdemo\firstdart>dart run
Building package executable...
Built firstdart:firstdart.
pi = 3.141592653589793
e = 2.718281828459045
sin30° = 0.49999999999999994
max(2,9) = 9
min(2,9) = 2
Random integer 0~9：9
[0,1) floating point：0.08331912429354282
Random boolean：falseCode language: JavaScript (javascript)

The dart:math Library