num_utilities

A collection of extension methods for nums, ints, and doubles; and iterables of nums, ints, and doubles.

See: list_utilities

Usage

import 'package:num_utilities/num_utilities.dart';

Numbers

nums, ints, and doubles were extended with the following methods/getters:

isPositive

isPositive returns true if the number's sign is positive.

final numA = 5;
print(numA.isPositive); // true

final numB = -5;
print(numB.isPositive); // false

equals

equals is equivalent to the == operator, but has an optional parameter to round the numbers before comparing them, by calling roundTo (see below.)

final numA = 5.556;
final numB = 5.557;
print(numA.equals(numB)); // false
print(numA.equals(numB, 100)); // true

isWithin

isWithin returns true if the number matches or is within the range of any of the parts defined in the provided expression.

The provided expression must be a string of numbers and/or ranges separated by commas.

final value = 7;
print(value.isWithin('0,2,4,6')); // false
print(value.isWithin('1,2,6-8,10')); // true
print(value.isWithin('0-4,7,12-15')); // true

isWithinRange

isWithinRange returns true if this number is within the range of the provided start and end values.

final value = 7;
print(value.isWithinRange(4, 8)); // true
print(value.isWithinRange(8, 4)); // true
print(value.isWithinRange(2, 6)); // false

roundTo

roundTo rounds the number by the value: (number * value).round() / value

final number = 5.556;
print(number.roundTo(10)); // 5.6

roundToPrecision

roundToPrecision rounds the number to the specified number of decimal points.

final number = 5.5567893;
print(number.roundToPrecision(3)); // 5.557

Iterables

Iterables of nums, ints, and doubles were extended with the following methods:

sum

The sum method returns the sum of all of the values in the iterable.

final list = [1, 2, 3, 4, 5];
print(list.sum()); // 15

absSum

The absSum method returns the sum of all of the absolute values in the iterable.

absSum has an optional parameter to invert the returned value.

final list = [1, -2, 3, -4, 5];
print(list.absSum()); // 15
print(list.absSum(false)); // 15
print(list.absSum(true)); // -15
print(list.sum()); // 3

highest

The highest getter returns the highest value in the iterable.

final list = [1, 2, 3, 4, 5];
print(list.highest); // 5

lowest

The lowest getter returns the lowest value in the iterable.

final list = [1, 2, 3, 4, 5];
print(list.lowest); // 1

Range

The Range object defines a range of numbers between specified min and max values, and has convienence methods for generating numbers within the range and for interpolating values within the range.

final range = Range(5, 15);
print(range.min); // 5
print(range.max); // 15

span

The span getter returns the difference between the min and max values.

print(range.span); // 10

random

The random method will output a number between the min value, inclusive, and the max value, exclusive.

random accepts an optional seed value.

print(range.random());
print(range.random(seed));

secureRandom

The secureRandom method will output a cryptographically secure number between the min value, inclusive, and max value, exclusive.

print(range.secureRandom());

interpolate

The interpolate method returns a List of numbers spanning a defined number of steps between the min and max values.

print(range.interpolate(5)); // [5.0, 7.0, 9.0, 11.0, 13.0]

inclusive

interpolate's inclusive parameter can be used to include the max number within the output List.

print(range.interpolate(5, inclusive: true)); // [5.0, 7.0, 9.0, 11.0, 13.0, 15.0]

randomize

interpolate's randomize parameter can be used to apply randomness to the output numbers, where a value of 0.0 doesn't apply any randomness to the numbers, while a value of 1.0 will randomize the output numbers within the entire range of the radius around each step.

print(range.interpolate(5, randomize: 1.0)); // [5.23, 6.18, 8.27, 10.27, 13.46]