I`m new to JavaScript and I need some help extracting the ID from URL using JavaScript for a gallery.
This is the link: www.shinylook.ro/produs/44/mocasini-barbati.html.
I need that number 44 in a variable.
You have to use the location object to get the URL, after that, you can use split to split the URL on the slashes.
location.pathname.split('/')[2] // Returns 44 in your example
You can do that with String#split or with a regular expression.
String#split lets you split a string on a delimiter and get an array as a result. So in your case, you could split on / and get an array where 44 would be at index 2.
Regular expressions let you do much more complicated matching and extraction, as shown by the various demos on the linked page. For instance,
var str = "www.shinylook.ro/produs/44/mocasini-barbati.html";
var m = /produs\/(\d+)\//.exec(str);
if (m) {
// m[1] has the number (as a string)
}
In both cases, the number will be a string. You can parse it with parseInt, e.g. n = parseInt(s, 10) (assuming it's base 10).
Related
I'm doing a small javascript method, which receive a list of point, and I've to read those points to create a Polygon in a google map.
I receive those point on the form:
(lat, long), (lat, long),(lat, long)
So I've done the following regex:
\(\s*([0-9.-]+)\s*,\s([0-9.-]+)\s*\)
I've tested it with RegexPal and the exact data I receive:
(25.774252, -80.190262),(18.466465, -66.118292),(32.321384, -64.75737),(25.774252, -80.190262)
and it works, so why when I've this code in my javascript, I receive null in the result?
var polygons="(25.774252, -80.190262),(18.466465, -66.118292),(32.321384, -64.75737),(25.774252, -80.190262)";
var reg = new RegExp("/\(\s*([0-9.-]+)\s*,\s([0-9.-]+)\s*\)/g");
var result = polygons.match(reg);
I've no javascript error when executing(with debug mode of google chrome). This code is hosted in a javascript function which is in a included JS file. This method is called in the OnLoad method.
I've searched a lot, but I can't find why this isn't working. Thank you very much!
Use a regex literal [MDN]:
var reg = /\(\s*([0-9.-]+)\s*,\s([0-9.-]+)\s*\)/g;
You are making two errors when you use RegExp [MDN]:
The "delimiters" / are should not be part of the expression
If you define an expression as string, you have to escape the backslash, because it is the escape character in strings
Furthermore, modifiers are passed as second argument to the function.
So if you wanted to use RegExp (which you don't have to in this case), the equivalent would be:
var reg = new RegExp("\\(\\s*([0-9.-]+)\\s*,\\s([0-9.-]+)\\s*\\)", "g");
(and I think now you see why regex literals are more convenient)
I always find it helpful to copy and past a RegExp expression in the console and see its output. Taking your original expression, we get:
/(s*([0-9.-]+)s*,s([0-9.-]+)s*)/g
which means that the expressions tries to match /, s and g literally and the parens () are still treated as special characters.
Update: .match() returns an array:
["(25.774252, -80.190262)", "(18.466465, -66.118292)", ... ]
which does not seem to be very useful.
You have to use .exec() [MDN] to extract the numbers:
["(25.774252, -80.190262)", "25.774252", "-80.190262"]
This has to be called repeatedly until the whole strings was processed.
Example:
var reg = /\(\s*([0-9.-]+)\s*,\s([0-9.-]+)\s*\)/g;
var result, points = [];
while((result = reg.exec(polygons)) !== null) {
points.push([+result[1], +result[2]]);
}
This creates an array of arrays and the unary plus (+) will convert the strings into numbers:
[
[25.774252, -80.190262],
[18.466465, -66.118292],
...
]
Of course if you want the values as strings and not as numbers, you can just omit the +.
How can i change the character after "#overlay/" and before "/" after that first one?
var x = "www.foo.com/#overlay/2/";
x.replace(/#overlay\/([^]*)\//, "1"); // i'm expecting: www.foo.com/#overlay/1/
I'm using this code, but no success. I don't understand that much from regex.
I've searched some questions but without success.
I would not use a regular expression here. You can just use .split().
var url, newUrl, peices;
url = 'www.foo.com/#overlay/2/';
// Split the string apart by /
peices = url.split('/');
// Changing the 3 element in the array to 1, it was originally 2.
peices[2] = 1;
// Let's put it back together...
newUrl = peices.join('/');
You're making 3 mistakes :
you're replacing too much
you don't use the returned value. replace doesn't change the passed string (strings are immutable) but returns a new one
you forgot to precise in your capturing group when to stop (in fact it doesn't even have to be a capturing group)
You can do this :
x = x.replace(/(#overlay\/)[^\/]*\//, "$11/");
$1 here refers to the first captured group, so that you don't have to type it in the replacement string.
For example it changes
"www.foo.com/#overlay/2/rw/we/2345"
into
"www.foo.com/#overlay/1/rw/we/2345"
I've found a few similar questions, but none of them are clean one-liners, which I feel should be possible. I want to split a string at the last instance of specific character (in my case .).
var img = $('body').attr('data-bg-img-url'); // the string http://sub.foo.com/img/my-img.jpg
var finalChar = img.split( img.split(/[.]+/).length-1 ); // returns int 3 in above string example
var dynamicRegex = '/[.$`finalChar`]/';
I know I'm breaking some rules here, wondering if someone smarter than me knows the correct way to put that together and compress it?
EDIT - The end goal here is to split and store http://sub.foo.com/img/my-img and .jpg as separate strings.
In regex, .* is greedy, meaning it will match as much as possible. Therefore, if you want to match up to the last ., you could do:
/^.*\./
And from the looks, you are trying to get the file extension, so you would want to add capture:
var result = /^.*\.(.*)$/.exec( str );
var extension = result[1];
And for both parts:
var result = /^(.*)\.(.*)$/.exec( str );
var path = result[1];
var extension = result[2];
You can use the lastIndexOf() method on the period and then use the substring method to obtain the first and second string. The split() method is better used in a foreach scenario where you want to split at all instances. Substring is preferable for these types of cases where you are breaking at a single instance of the string.
I have a string that looks something like this
Hey this is my 1.20 string
I'm trying to just extract 1.20 from it.
What's the best way to do this?
I've tried something like this, but I get the value of 1.20,20 rather than just 1.20
var query = $(".query_time").html();
var matches = query.match(/\d.(\d+)/);
The result of the match function is an array, not a string. So simply take
var nb = query.match(/\d.(\d+)/)[0];
BTW, you should also escape the dot if you want to have more precise match :
var nb = query.match(/\d\.(\d+)/)[0];
or this if you want to accept commas (depends on the language) :
var nb = query.match(/\d[\.,](\d+)/)[0];
But the exact regex will be based on your exact needs, of course and to match any number (scientific notation ?) I'd suggest to have a look at more complex regex.
The value of matches is actually [ "1.20", "20" ] (which is an array). If you print it, it will get converted to a string, hence the 1.20,20.
String.match returns null or an array of matches where the first index is the fully matched part and then whichever parts you wanted. So the value you want is matches[0].
Try the following
var nb = query.match(/\d\.\d+/)[0]; // "1.20"
You need to escape . because that stands for any character.
Remove the capture group (\d+) and the second match is not returned
Add [0] index to retrieve the match
I am doing it wrong. I know.
I want to assign the matched text that is the result of a regex to a string var.
basically the regex is supposed to pull out anything in between two colons
so blah:xx:blahdeeblah
would result in xx
var matchedString= $(current).match('[^.:]+):(.*?):([^.:]+');
alert(matchedString);
I am looking to get this to put the xx in my matchedString variable.
I checked the jquery docs and they say that match should return an array. (string char array?)
When I run this nothing happens, No errors in the console but I tested the regex and it works outside of js. I am starting to think I am just doing the regex wrong or I am completely not getting how the match function works altogether
I checked the jquery docs and they say that match should return an array.
No such method exists for jQuery. match is a standard javascript method of a string. So using your example, this might be
var str = "blah:xx:blahdeeblah";
var matchedString = str.match(/([^.:]+):(.*?):([^.:]+)/);
alert(matchedString[2]);
// -> "xx"
However, you really don't need a regular expression for this. You can use another string method, split() to divide the string into an array of strings using a separator:
var str = "blah:xx:blahdeeblah";
var matchedString = str.split(":"); // split on the : character
alert(matchedString[1]);
// -> "xx"
String.match
String.split