```dart
import 'dart:math' as math;

var random = new math.Random();
random.nextDouble(); // Between 0.0 and 1.0: [0, 1)
random.nextInt(10);  // Between 0 and 9.

var random = new math.Random();
random.nextBool();  // true or false
```

## 生成随机布尔值

```dart
import 'dart:math' as math;

var random = new math.Random();
random.nextBool();  // true or false
```


dart.md

```js
// Math.random()返回0到1之间的一个伪随机数，可能等于0，但是一定小于1。
Math.random(); // 0.7151307314634323

// 任意范围的随机数生成函数
function getRandomArbitrary(min, max) {
  return Math.random() * (max - min) + min;
}
getRandomArbitrary(1.5, 6.5);
// 2.4942810038223864

// 任意范围的随机整数生成函数
function getRandomInt(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}
getRandomInt(1, 6); // 5

// 返回随机字符的例子
function random_str(length) {
  var ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  ALPHABET += "abcdefghijklmnopqrstuvwxyz";
  ALPHABET += "0123456789-_";
  var str = "";
  for (var i = 0; i < length; ++i) {
    var rand = Math.floor(Math.random() * ALPHABET.length);
    str += ALPHABET.substring(rand, rand + 1);
  }
  return str;
}
random_str(6); // "NdQKOr"

// 返回随机字符另一个实现
const str = "abcdefghijklmnopqrstuvwxyz9876543210";
const l = 6;
// [...Array(l)].map(()=>str.charAt(Math.floor(Math.random() * str.length))).join('');
[...Array(l)].map(() => str[~~(Math.random() * str.length)]).join("");
```

## 生成随机字符串

```js
// 返回随机字符的例子
function random_str(length) {
  var ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  ALPHABET += "abcdefghijklmnopqrstuvwxyz";
  ALPHABET += "0123456789-_";
  var str = "";
  for (var i = 0; i < length; ++i) {
    var rand = Math.floor(Math.random() * ALPHABET.length);
    str += ALPHABET.substring(rand, rand + 1);
  }
  return str;
}
random_str(6); // "NdQKOr"

// 返回随机字符另一个实现
const str = "abcdefghijklmnopqrstuvwxyz9876543210";
const l = 6;
// [...Array(l)].map(()=>str.charAt(Math.floor(Math.random() * str.length))).join('');
[...Array(l)].map(() => str[~~(Math.random() * str.length)]).join("");
```


js.md

```sh
>>> import random
>>> random.choice(['apple', 'pear', 'banana'])
'apple'
>>> random.sample(range(100), 10)   # sampling without replacement
[30, 83, 16, 4, 8, 81, 41, 50, 18, 33]
>>> random.random()    # random float
0.17970987693706186
>>> random.randrange(6)    # random integer chosen from range(6)
4

# statistics 模块计算数值数据的基本统计属性（均值，中位数，方差等）:
>>> import statistics
>>> data = [2.75, 1.75, 1.25, 0.25, 0.5, 1.25, 3.5]
>>> statistics.mean(data)
1.6071428571428572
>>> statistics.median(data)
1.25
>>> statistics.variance(data)
1.3720238095238095
```

## 随机选择子对象

```sh
>>> import random
>>> random.choice(['apple', 'pear', 'banana'])
'apple'
```
