javascript从字符串中提取主题标签

Question

I have a string received from backend, and I need to extract hashtags. The tags are written in one of these two forms

type 1. #World is a #good #place to #live.
type 2. #World#place#live.

I managed to extract from first type by : str.replace(/#(\\S*)/g how can i change the second format to space seperated tags as well as format one?

basically i want format two to be converted from

 #World#place#live.

to

 #World #place #live.

Answer 1

You can use String.match , with regex #\\w+ :

 var str = ` type 1. #World is a #good #place to #live. type 2. #World#place#live.` var matches = str.match(/#\\w+/g) console.log(matches) 

\\w+ matches any word character [a-zA-Z0-9_] more than once, so you might want to tweak that.

Once you have the matches in an array you can rearrange them to your likes.

Answer 2

The pattern #(\\S*) will match a # followed by 0+ times a non whitespace character in a captured group. That would match a single # as well. The string #World#place#live. contains no whitespace character so the whole string will be matched.

You could match them instead by using a negated character class. Match #, followed by a negated character class that matches not a # or a whitespace character.

#[^#\s]+

Regex demo

 const strings = [ "#World is a #good #place to #live.", "#World#place#live." ]; let pattern = /#[^#\\s]+/g; strings.forEach(s => { console.log(s.match(pattern)); }); 

Answer 3

How about that using regex /#([\\w]+\\b)/gm and join by space like below to extract #hastags from your string? OR you can use str.replace(/\\b#[^\\s#]+/g, " $&") as commented by @Wiktor

 function findHashTags(str) { var regex = /#([\\w]+\\b)/gm; var matches = []; var match; while ((match = regex.exec(str))) { matches.push(match[0]); } return matches; } let str1 = "#World is a #good #place to #live." let str2 = "#World#place#live"; let res1 = findHashTags(str1); let res2 = findHashTags(str2); console.log(res1.join(' ')); console.log(res2.join(' '));