Since Math.random( ) generates a value between 0 and 1,you need only multiply it by the upper bound of the range of numbers you want to produce (26 for the letters in the alphabet) and add an offset to establish the lower bound.

• 由于Math.；random()会产生0到1之间的一个值，所以只需将其乘以想获得的最大随机数(对于英语字母，这个数字是26)，再加上一个偏移量，得到最小的随机数。