How to Generate Random Numbers and range of numbers in Dart or Flutter Programming with example

This tutorial shows multiple ways to Generate Random Numbers in the Dart programming language.

A random number is a unique number generated between a minimum and maximum value for multiple requests

The returned number is always between the ranges of values provided.

Dart random Number Generator example

Dart provides dart:math that contains a Random class to provide a random generator. It provides the nextInt method takes a maximum value and returns a random number.

int nextInt(int max)

minimum number is taken as zero as a minimum and the maximum number is the given max value.

Here is a simple example to generate Random Generator

import 'dart: math';

main() {
  var random = Random();
  print(random.nextInt(10)); //Random number between 0 to 10
  print(random.nextInt(100)); //Random number between 0 to 100
  print(random.nextInt(200)); //Random number between 0 to 100
  print(random.nextInt(1000)); //Random number between 0 to 1000
}

• Imported the dart:math package into a program using the import keyword
• Create a Random variable using the var keyword
• Call nextInt() with seed number.
• Random Number always generated between 0 to seed number

Output:

4
70
47
294

Dart random Number Generator within a range example

This is a generating random number between min and max value of ranges example.

import 'dart:math';

main() {
  var random = Random();
  int min = 10;
  int max = 20;
  var randomNumber = min + random.nextInt(max - min);
  print("$randomNumber is random number between $min and $max");
  print(randomNumber);
}

Output:

19 is a random number between 10 and 20
19

How to generate a random number in dart excluding a particular number?

For example, You want to generate a random number between 0 to 10 and the generated random number must not be 5.

Here is an example program to generate a Random Number excluding given number

import 'dart:math';

main() {
  var random = Random();
  var excludeNumber = 5;
  var randomNumber;
  do {
    randomNumber = random.nextInt(10);
  } while (randomNumber == excludeNumber);
  print(randomNumber);
}