Question

我正在尝试使用RegExp，以便稍后可以插入字符串变量。但是，即使没有该变量的第一次尝试也将不起作用。缺少什么？

有一个很好的jsbin链接可以显示行为。

const DOCS = [
    "My Report – March 2019.pdf",
    "My Report – May 2019.pdf",
    "My Diary - April-May 2019.pdf",
    "My Diary - February-March 2019.pdf"
]

const title_month_year = new RegExp("(.*) - (January|February|March|April|May|June|July|August|September|October|November|December) (19|20\d{2})")


DOCS.forEach(
    mag = mag.replace(/–/g, "-");
//  if (title_month_year.test(mag)) {   <--- does not match
    if (/(.*) - (January|February|March|April|May|June|July|August|September|October|November|December) (19|20\d{2})/.test(mag)) {
        console.log('we have a match');   
    }

https://jsbin.com/lomolew/edit?js,console

Answer 1

const DOCS = [
    "My Report – March 2019.pdf",
    "My Report – May 2019.pdf",
    "My Diary - April-May 2019.pdf",
    "My Diary - February-March 2019.pdf"
]

const months = {
    "January": "01",
    "Jan": "01",
    "February": "02",
    "Feb": "02",
    "March": "03",
    "Mar": "03",
    "April": "04",
    "Apr": "04",
    "May": "05",
    "June": "06",
    "Jun": "06",
    "July": "07",
    "Jul": "07",
    "August": "08",
    "Aug": "08",
    "September": "09",
    "Sep": "09",
    "October": "10",
    "Oct": "10",
    "November": "11",
    "Nov": "11",
    "December": "12",
    "Dec": "12"
}


let docsCopy = DOCS.map(m => {

    var mReplace = m.replace(/^(.+)+(?:\s[-–]\s)+((?:\w+)+(?:-)?(?:\w+)?)+\s(\d+)+(.+)/, (match, p1, p2, p3, p4) => {
        var reg = /(\w+)?(?:[-–](\w+))?/

        var p2C = p2.replace(reg, (match, $1, $2) => {
            var p2Months = $2 ? [months[$1], months[$2]] : [months[$1]]
            return p2Months.join('-')
        })

        return p1 + ' ' + p3 + '-' + p2C + p4

    })

    return mReplace



});

console.log(docsCopy)

Answer 2

正如第四只鸟所指出的，您正在使用另一种类型的hypen。您可以做的就是调整您的正则表达式，使其包含两种类型的连字符： const title_month_year = new RegExp("(.*) (-|–) (January|February|March|April|May|June|July|August|September|October|November|December) (19|20\d{2})")

请注意，在解决方案中，您的分组值将在第一个条目之后偏移一个（因此，现在您不再拥有3个元素，而是3个，第一个是hypen前面的内容，第二个是hypen类型，第三个是月份，第四个是年份。

或者只是寻找一个字符而不是一个连字符： const title_month_year = new RegExp("(.*) . (January|February|March|April|May|June|July|August|September|October|November|December) (19|20\d{2})")

Answer 3

您忘了逃避\ d {2}

它应该在RegExp字符串内\\ d {2}。

此RegExp字符串是否需要转义？

3 个答案: