【Codewars】＜6kyu＞Detect Pangram

一、题目

A pangram is a sentence that contains every single letter of the alphabet at least once. For example, the sentence “The quick brown fox jumps over the lazy dog” is a pangram, because it uses the letters A-Z at least once (case is irrelevant).
Given a string, detect whether or not it is a pangram. Return True if it is, False if not. Ignore numbers and punctuation.


这道题要我们实现的是，判断字符串中是否包含·a-z至少一次（不区分大小写），是的话返回true，否则返回false

二、例子

var string = "The quick brown fox jumps over the lazy dog."
isPangram(string)