Is it possible to add (+1) to a (substring) with regex/replace? For instance, if I have a string (the window location in this case) that ends in #img-{digit}, is it possible with regex to replace the digit with what it was +1?
I can match the hash like this, but I'm not sure how I can extract the number (which can be more than 2 digits! e.g. 12).
var loc = window.location,
locstr = loc.match(/#img-\d+/),
// untested:
locrep = locstr.replace(/\d/, Number($1) + 1);
Let's say that my current hash is #img-4, then I want a JS snippet that changes it to #img-5.
Use a callback in replace:
var locrep = locstr.replace(/\d+/, function($0) { return Number($0) + 1; });
//=> #img-5
Or else:
var locrep = locstr.replace(/(#img-)(\d+)/i,
function($0, $1, $2) { return $1 + (Number($2) + 1); });
//=> #img-5
Since you have the string like #img-{digit}, you can use split with - like this
var loc = window.location,
locstr = loc.split("-");
var newloc = locstr[0]+parseInt(locstr[1])+1;
Note, window.location returns window.location object ; e.g.,
console.log(typeof window.location, typeof window.location.hash);
Try
var loc = window.location.hash
, locrep = loc.match(/[^\d]/g).join("") + (1+Number(loc.match(/\d/g).join("")));
Related
I have this URL
http://192.168.22.124:3000/temp/box/c939c38adcf1873299837894214a35eb
I want to replace the last part of my URL which is c939c38adcf1873299837894214a35eb with something else.
How can I do it?
Try this:
var url = 'http://192.168.22.124:3000/temp/box/c939c38adcf1873299837894214a35eb';
somethingelse = 'newhash';
var newUrl = url.substr(0, url.lastIndexOf('/') + 1) + somethingelse;
Note, using the built-in substr and lastIndexOf is far quicker and uses less memory than splitting out the component parts to an Array or using a regular expression.
You can follow this steps:
split the URL with /
replace the last item of array
join the result array using /
var url = 'http://192.168.22.124:3000/temp/box/c939c38adcf1873299837894214a35eb';
var res = url.split('/');
res[res.length-1] = 'someValue';
res = res.join('/');
console.log(res);
Using replace we can try:
var url = "http://192.168.22.124:3000/temp/box/c939c38adcf1873299837894214a35eb";
var replacement = 'blah';
url = url.replace(/(http.*\/).*/, "$1" + replacement);
console.log(url);
We capture everything up to and including the final path separator, then replace with that captured fragment and the new replacement.
Complete guide:
// url
var urlAsString = window.location.href;
// split into route parts
var urlAsPathArray = urlAsString.split("/");
// create a new value
var newValue = "routeValue";
// EITHER update the last parameter
urlAsPathArray[urlAsPathArray.length - 1] = newValue;
// OR replace the last parameter
urlAsPathArray.pop();
urlAsPathArray.push(newValue);
// join the array with the slashes
var newUrl = urlAsPathArray.join("/");
// log
console.log(newUrl);
// output
// http://192.168.22.124:3000/temp/box/routeValue
You could use a regular expression like this:
let newUrl = /^.*\//.exec(origUrl)[0] + 'new_ending';
I find it hard to believe this hasn't been asked but I can find no references anywhere. I need to add a URI hash fragment and update the value if it already is in the hash. I can currently get it to add the hash but my regex doesn't appear to catch if it exists so it adds another instead of updating.
setQueryString : function() {
var value = currentPage;
var uri = window.location.hash;
var key = "page";
var re = new RegExp("([#&])" + key + "=.*#(&|$)", "i");
var separator = uri.indexOf('#') !== -1 ? "&" : "#";
if (uri.match(re)) {
return uri.replace(re, '$1' + key + "=" + value + '$2');
}
else {
return uri + separator + key + "=" + value;
}
},
Also if this can be made any cleaner while preserving other url values/hashes that would be great.
example input as requested
Starting uri value:
www.example.com#page=1 (or no #page at all)
then on click of "next page" setQueryString gets called so the values would equal:
var value = 2;
var uri = '#page1'
var key = 'page'
So the hopeful output would be '#page2'.
As to your regex question, testing if the pattern #page=(number) or &page=(number) is present combined with capturing the number, can be done with the regex /[#&]page\=(\d*)/ and the .match(regex) method. Note that = needs escaping in regexes.
If the pattern exists in the string, result will contain an array with the integer (as a string) at result[1]. If the pattern does not exist, result will be null.
//match #page=(integer) or &page=(integer)
var test = "#foo=bar&page=1";
var regex = /[#&]page\=(\d*)/;
var result = test.match(regex);
console.log(result);
If you want to dynamically set the key= to something other than "page", you could build the regex dynamically, like the following (note that backslashes needs escaping in strings, making the code a bit more convoluted):
//dynamically created regex
var test = "#foo=bar&page=1";
var key = "page"
var regex = new RegExp("[#&]" + key + "\\=(\\d*)");
var result = test.match(regex);
console.log(result);
I am taking first steps with regular expressions. I am trying to increment the last digit in a url string but for some reason I cant figure out I increment other digits.
Example
string: http://example.com/18-something-something/6
should become: http://example.com/18-something-something/7
in practice: http://example.com/19-something-something/7
As you can see, 18 turned to 19 which is what im trying to avoid.
This is my JS:
function isNumeric(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}
jQuery(document).ready(function() {
url = window.location.href;
var newrl = url.replace(/(\d+)+/g, function(match, number) {
return parseInt(number) + 1;
});
var m = url.match(/\/([^\/]+)[\/]?$/);
link = jQuery('a[class=nextpostslink]').attr('href');
if (!isNumeric(m[1])) {
jQuery('.post-content').find('img:first').wrap(jQuery("<div class='slideshow-wrapper'><a href=2>").attr("href", link));
jQuery('.post-content').find('img:first').after('<div id="start-slideshow"><img src="chevron.png"></div>');
} else {
jQuery('.post-content').find('img:first').wrap(jQuery("<div class='slideshow-wrapper'><a href=" + newrl + ">").attr("href", link));
}
});
Any idea what am I missing? thx
You don't want to have a global match (g), but removing that flag alone won't help.
If you want match with and without query parameter, then you need to make sure that it is either at the end of the string $ or right before the query parameters ? so your RegExp has to look like this:
var url = 'http://example.com/18-something-something/6?param=34';
var newrl = url.replace(/(\d+)($|\?)/, function(match, number, questionmark) {
return String(++number) + questionmark;
});
console.log(newrl);
You should use /(\d+)$/ as a regex to increment only the last digit.
I would not do this with regular expressions, truthfully.
I'd do something like:
var url = "http://example.com/18-something-something/6";
function advanceUrl(url) {
// Split the URL into chunks
var chunks = url.split("/");
// Get the last segment of the URL
var lastPage = chunks.pop();
// Increment it
lastPage++;
// And put it back
chunks.push(lastPage);
// Re-create the URL
var newUrl = chunks.join("/");
// Log it
console.log(newUrl);
// Return it.
return newUrl;
}
advanceUrl(url);
I have a URL say
dummy URL
http://www.google.com/?v=as12&&src=test&img=test
Now I want to remove the &src=test& part alone.I know we can use indexof but somehow I could not get the idea of getting the next ampersand(&) and removing that part alone.
Any help.The new URL should look like
http://www.google.com/?v=as12&img=test
What about using this?:
http://jsfiddle.net/RMaNd/8/
var mystring = "http://www.google.com/?v=as12&&src=test&img=test";
mystring = mystring.replace(/&src=.+&/, ""); // Didn't realize it isn't necessary to escape "&"
alert(mystring);
This assumes that "any" character will come after the "=" and before the next "&", but you can always change the . to a character set if you know what it could be - using [ ]
This also assumes that there will be at least 1 character after the "=" but before the "&" - because of the +. But you can change that to * if you think the string could be "src=&img=test"
UPDATE:
Using split might be the correct choice for this problem, but only if the position of src=whatever is still after "&&" but unknown...for example, if it were "&&img=test&src=test". So as long as the "&&" is always there to separate the static part from the part you want to update, you can use something like this:
http://jsfiddle.net/Y7LdG/
var mystring1 = "http://www.google.com/?v=as12&&src=test&img=test";
var mystring2 = "http://www.google.com/?v=as12&&img=test&src=test";
var final1 = removeSrcPair(mystring1);
alert(final1);
var final2 = removeSrcPair(mystring2);
alert(final2);
function replaceSrc(str) {
return str.replace(/src=.*/g, "");
}
function removeSrcPair(orig) {
var the_split = orig.split("&&");
var split_second = the_split[1].split("&");
for (var i = split_second.length-1; i >= 0; i--) {
split_second[i] = replaceSrc(split_second[i]);
if (split_second[i] === "") {
split_second.splice(i, 1);
}
}
var joined = split_second.join("&");
return the_split[0] + "&" + joined;
}
This still assumes a few things - the main split is "&&"...the key is "src", then comes "=", then 0 or more characters...and of course, the key/value pairs are separated by "&". If your problem isn't this broad, then my first answer seems fine. If "src=test" won't always come first after "&&", you'd need to use a more "complex" Regex or this split method.
Something like:
url = "http://www.google.com/?v=as12&&src=test&img=test"
firstPart = url.split('&&')[0];
lastPart = url.split('&&')[1];
lastPart = lastPart.split('&')[1];
newUrl = firstPart+'&'+lastPart;
document.write(newUrl);
Details: Use the split method.
Solution Edited: I changed the below to test that the last query string exists
var url = "http://www.google.com/?v=as12&&src=test&img=test";
var newUrl;
var splitString = url.split('&');
if (splitString.length > 3)
{
newURL = splitString[0] + "&" + splitString[3];
}
else
{
newURL = splitString[0];
}
I'm trying to write a function that will remove a query argument from a url in javascript. I think I have it using regex, but I'm not sure if I've missed anything. Also, I can't shake the feeling that there was probably a better way to do this that didn't involve me messing around with regex half the day and running the risk of later finding out that I didn't take some kind of corner case into account.
remove_query_argument = function(url, arg){
var query_arg_regex;
// Remove occurences that come after '&' symbols and not the first one after the '?'
query_arg_regex = new RegExp('&' + arg + '=[^(?:&|$)]*', 'ig');
url = url.replace(query_arg_regex, '');
// remove the instance that the argument to remove is the first one
query_arg_regex = new RegExp('[?]' + arg + '[^(?:&|$)]*(&?)', 'i');
url = url.replace(query_arg_regex, function (match, capture) {
if( capture != '&' ){
return '';
}else{
return '?'
}
});
return url;
}
Does anyone see any problems with this code or would like to suggest a better implementation or way of going about this?
Thanks!
If you have a lot of URL-related operations, you better try this awesome js library https://github.com/medialize/URI.js
Given a percent-encoded URL, the following function will remove field-value pairs from its query string:
var removeQueryFields = function (url) {
var fields = [].slice.call(arguments, 1).join('|'),
parts = url.split( new RegExp('[&?](' + fields + ')=[^&]*') ),
length = parts.length - 1;
return parts[0] + '?' + (length ? parts[length].slice(1) : '');
}
Some examples:
var string = 'http://server/path/program?f1=v1&f2=v2';
removeQueryFields( string, 'f1' ); // 'http://server/path/program?f2=v2'
removeQueryFields( string, 'f2' ); // 'http://server/path/program?f1=v1'
removeQueryFields( string, 'f1', 'f2' ); // 'http://server/path/program'