Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 10000. **Example 1:** ~~~ Input: "abab" Output: True Explanation: It's the substring "ab" twice. ~~~ **Example 2:** ~~~ Input: "aba" Output: False ~~~ **Example 3:** ~~~ Input: "abcabcabcabc" Output: True Explanation: It's the substring "abc" four times. (And the substring "abcabc" twice.) ~~~   ``` \1 就是匹配到至少2次 ``` ``` /** * @param {string} s * @return {boolean} */ var repeatedSubstringPattern = function(s) { var reg = /^(\w+)\1+$/ return reg.test(s) }; ```   ``` var repeatedSubstringPattern = function(s) { return s.repeat(2).slice(1,-1).includes(s); }; ```