Example data                         expected output   sds-rwewr-dddd-cash0-bbb              cash0rrse-cash1-nonre                      cash1loan-snk-cash2-ssdd                   cash2garb-cash3-dfgfd                      cash3loan-unwan-cash4-something            cash4通用模式在這里，需要在給定字符串的最后一個連字符之前提取幾個字符。var regex1= /.*(?=(?:-[^-]*){1}$)/g ;       //output will be "ds-rwewr-dddd-cash0" from "sds-rwewr-dddd-cash0-bbb  "var regex2 = /\w[^-]*$/g ;       //output will be "cash0" from "ds-rwewr-dddd-cash0"var res =regex2.exec(regex1.exec(sds-rwewr-dddd-cash0-bbb)) //output will cash0雖然上面嵌套的正則表達式按預期工作但可能不是優化的。因此，對于優化正則表達式的任何幫助將不勝感激