How to get a random number from range in dart?

Question

How does one get a random number within a range similar to c# Random.Next(int min, int max);

Answer 1

It can be achieved exactly as you intended by creating extension on int to get random int value. For example:

import 'dart:math';

import 'package:flutter/foundation.dart';

extension RandomInt on int {
  static int generate({int min = 0, @required int max}) {
    final _random = Random();
    return min + _random.nextInt(max - min);
  }
}

And you can use this in your code like so:

List<int> rands = [];
for (int j = 0; j < 19; j++) {
  rands.add(RandomInt.generate(max: 50));
}

Note that static extension methods can't be called on type itself (e.g. int.generate(min:10, max:20)), but instead you have to use extension name itself, in this example RandomInt. For detailed discussion, read here.

Answer 2

Generates a random integer uniformly distributed in the range from [min] to [max], both inclusive.

int nextInt(int min, int max) => min + _random.nextInt((max + 1) - min);

Answer 3

To generate a random double within a range, multiply a random int with a random double.

import 'dart:math';
Random random = new Random();
int min = 1, max = 10;
double num = (min + random.nextInt(max - min)) * random.nextDouble();