摘要：
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice The slice() method returns a shallow copy of a portion of 阅读全文
摘要：
What's the difference between using “let” and “var”? ECMAScript 6 introduced the let statement. I've heard that it's described as a local variable, bu 阅读全文