我如何从第三个“ /”之后获取字符串

Question

Totally new to programming so kindly excuse the silly question. I have this URL http://www.blahblah.com/some/thing/blah ..

Now i need the string that appears after the third"/" ie., just "/some/thing".. I dont want to go from reverse as the URL is different for each page but the protocol and the host name is the same.. Is there a way i can extract "/some/thing" along using Javascript.. Appreciate any help.. Thanks!!

Answer 1

var part = string.split('/')[2]

Or more complicated:

var string = "/a/b/c/d/e/d"
var arr1 = string.split('/')
var arr2 = []
for (i in  arr1)
{
  if (arr1[i].length > 0)
     arr2.push(arr1[i])
}
var part = arr2[2]

Answer 2

using the string.split method: http://www.w3schools.com/jsref/jsref_split.asp

var str = "www.blah.com/blah/blah/thing/blah.php";
var arrayOfString = str.split("/");
alert(arrayOfString[2]); //coming back to do regex/substring for you

have fun! :)

By the way... if you are new to web development, www.w3schools.com was extremely good to me :)

so to respond to your edit you need to do something like this :

assuming above already:

alert(arrayOfString.slice(3).join("/"));

ok fixed it based on actual needs here.. but like i said, check out http://www.w3schools.com it really taught me some good basics.

to fix for the fail case in the comments do this before the split/slice/join:

if (str.substring(0,1) == "/"){ str = str.substring(1);}

Answer 3

I would use a simple regular expression here.

One way to get stuff after the third "/" just throw it away with everything before it .

Basic idea:

"/a/b/c/d/e/f".replace(/.*?\/.*?\/s.*?\//, "")
// -> "c/d/e/f"

Alternative #1, to reduce repeat:

"/a/b/c/d/e/f".replace(/(?:.*?\/){3}/, "")     

Alternative #2, if input can contain newlines:

"/a/b/c/d/e/f".replace(/(?:[^\/]*\/){3}/, "")

The *? qualifier means "don't be greedy" so . won't skip over / 's. It's not needed in the negative character class case because [^\\/] will never match / .

This could of course be written in a "less generic" form because because the real intent is just to git rid of the protocol/domain portions of the URI (the number of / 's is only an observed relationship):

"http://foo/a/b/c/d/e/f".replace(/https?:\/\/[^\/]*\/?/i, "")
// -> "a/b/c/d/e/f"

Note that the last \\/ has a ? after it so it will return "" for "http://foo" and the i is so it will match HTTP:// if that is used for some strange reason (completely optional, of course).

"HTTPS://foo".replace(/https?:\/\/[^\/]*\/?/i, "")
// -> ""

Happy coding!

---

Note: all of the above regular expressions will extract the content after the 3rd / , as stated in the question. They will need to be slightly modified to include the 3rd / in the result. Also, it helps to not ask XY questions.

Answer 4

var str = 'http://www.blahblah.com/some/thing/blah'
var afterThirdSlash = str.split('/').slice(3).join('/')

The split returns an array which is the string split on every / character. The slice selects the part of the array from the fourth element (since arrays are zero-based) onwards, since that corresponds to the part after the third slash. The join pieces these elements back together by re-inserting the / . Is this what you wanted?

Answer 5

如果您知道网址以“ http://www.blahblah.com/”开头，为什么不使用url.substring（24）？