Javascript只获取正则表达式中匹配的文本

Question

I have string like below

BANKNIFTY-13-FEB-2020-31200-ce

I want to convert the string to 13-FEB-31200-ce

so I tried below code

str.match(/(.*)-(?:.*)-(?:.*)-(.*)-(?:.*)-(?:.*)/g)

But its returning whole string

Answer 1

Two capture groups is probably the way to go. Now you have two options to use it. One is match which requires you to put the two pieces together

 var str = 'BANKNIFTY-13-FEB-2020-31200-ce' var match = str.match(/[^-]+-(\\d{2}-[AZ]{3}-)\\d{4}-(.*)/) // just reference the two groups console.log(`${match[1]}${match[2]}`) // or you can remove the match and join the remaining match.shift() console.log(match.join(''))

Or just string replace which you do the concatenation of the two capture groups in one line.

 var str = 'BANKNIFTY-13-FEB-2020-31200-ce' var match = str.replace(/[^-]+-(\\d{2}-[AZ]{3}-)\\d{4}-(.*)/, '$1$2') console.log(match)

Answer 2

Regex doesn't seem to be the most appropriate tool here. Why not use simple .split ?

 let str = 'BANKNIFTY-13-FEB-2020-31200-ce'; let splits = str.split('-'); let out = [splits[1], splits[2], splits[4], splits[5]].join('-'); console.log(out);

If you really want to use regexp,

 let str = 'BANKNIFTY-13-FEB-2020-31200-ce'; let splits = str.match(/[^-]+/g); let out = [splits[1], splits[2], splits[4], splits[5]].join('-'); console.log(out);

Answer 3

I would not use Regex at all if you know exact positions. Using regex is expensive and should be done differently if there is way. ( https://blog.codinghorror.com/regular-expressions-now-you-have-two-problems/ )

const strArr = "BANKNIFTY-13-FEB-2020-31200-ce".split("-"); // creates array
strArr.splice(0,1); // remove first item
strArr.splice(2,1); // remove 2020
const finalStr = strArr.join("-");

Answer 4

If the pattern doesn't need to be too specific.
Then just keep it simple and only capture what's needed.
Then glue the captured groups together.

 let str = 'BANKNIFTY-13-FEB-2020-31200-ce'; let m = str.match(/^\\w+-(\\d{1,2}-[AZ]{3})-\\d+-(.*)$/) let result = m ? m[1]+'-'+m[2] : undefined; console.log(result);

In this regex, ^ is the start of the string and $ the end of the string.

Answer 5

You can have something like this by capturing groups with regex:

 const regex = /(\\d{2}\\-\\w{3})(\\-\\d{4})(\\-\\d{5}\\-\\w{2})/ const text = "BANKNIFTY-13-FEB-2020-31200-ce" const [, a, b, c] = text.match(regex); console.log(`${a}${c}`)