Returns the average value of a list of numbers.
Use Iterable.reduce() to get the sum of all the numbers in a list, divide by Iterable.length to get the average.
代码实现
num average(List<num> nums){
return nums.reduce((num a, num b) => a + b) / nums.length;
}使用样例
average([1, 2, 3, 4]); // 2.5