根据正则表达式模式分割字符串

Question

I am new to using regular expression. Given the string, I am trying to achieve the following:

actStr1 = 'st1/str2/str3'
expStr1 = 'str3'

actStr2 = 'str1/str2/str3 // str4'
expStr2 = 'str3 // str4'

actStr3 = 'a1/b1/c1 : c2'
expStr3 = 'c1 : c2'

In both cases, i would like to find the last string delimited by '/'

ie, '/' like %s\\/%s . delimiter '/' having strings on both sides

result1 = 'str3 // str4'
result2 = 'str3'

I tried different patterns using regex, but it incorrectly returns 'str4' delimited by '//' .

How do I avoid this?

Thanks

Answer 1

Instead of using String.prototype.split() , try to use String.prototype.match() to directly target what you need:

 var testStrings = [ 'str1/str2/str3', 'str1/str2/str3 // str4', 'a1/b1/c1 : c2' ]; var re = new RegExp('[^/]*(?://+[^/]*)*$'); testStrings.forEach(function(elt) { console.log(elt.match(re)[0]); }); /* str3 str3 // str4 c1 : c2 */ 

Less straight forward, you can also use a replacement strategy with String.prototype.replace() . The idea is to remove all until the last slash not preceded and not followed by an other slash:

var re = new RegExp('(?:.*[^/]|^)/(?!/)');

testStrings.forEach(function(elt) {
    console.log(elt.replace(re, ''));
});

Answer 2

You could use a regex like this:

\/(\w+(?:$| .*))

Working demo

And grab the content from capturing group

Answer 3

I think you can resolve this considering using arrays too!

function lastSlug(str) {
  // remove the '//' from the string
  var b = str.replace('//', '');
  // find the last index of '/'
  var c = b.lastIndexOf('/')  + 1;
  // return anything after that '/' 
  var d = str.slice(c);
  return d;
}

Demo