This question already has answers here:
How do I replace all occurrences of a string in JavaScript?
(78 answers)
Fastest method to replace all instances of a character in a string [duplicate]
(14 answers)
Closed 1 year ago.
I'm trying to do replace in JavaScript using:
r = "I\nam\nhere";
s = r.replace("\n"," ");
But instead of giving me
I am here
as the value of s,
It returns the same.
Where's the problem??
As stated by the others the global flag is missing for your regular expression. The correct expression should be some thing like what the others gave you.
var r = "I\nam\nhere";
var s = r.replace(/\n/g,' ');
I would like to point out the difference from what was going on from the start.
you were using the following statements
var r = "I\nam\nhere";
var s = r.replace("\n"," ");
The statements are indeed correct and will replace one instance of the character \n. It uses a different algorithm. When giving a String to replace it will look for the first occurrence and simply replace it with the string given as second argument. When using regular expressions we are not just looking for the character to match we can write complicated matching syntax and if a match or several are found then it will be replaced. More on regular expressions for JavaScript can be found here w3schools.
For instance the method you made could be made more general to parse input from several different types of files. Due to differences in Operating system it is quite common to have files with \n or \r where a new line is required. To be able to handle both your code could be rewritten using some features of regular expressions.
var r = "I\ram\nhere";
var s = r.replace(/[\n\r]/g,' ');
use s = r.replace(/\\n/g," ");
Get a reference:
The "g" in the javascript replace code stands for "greedy" which means the replacement should happen more than once if possible
The problem is that you need to use the g flag to replace all matches, as, by default, replace() only acts on the first match it finds:
var r = "I\nam\nhere",
s = r.replace(/\n/g,' ');
To use the g flag, though, you'll have to use the regular expression approach.
Incidentally, when declaring variables please use var, otherwise the variables you create are all global, which can lead to problems later on.
.replace() needs the global match flag:
s = r.replace(/\n/g, " ");
It's working for me:
var s = r.split('\\n').join(' ');
replaceAll() is relative new, not supported in all browsers:
r = "I\nam\nhere";
s = r.replaceAll("\n"," ");
You can use:
var s = r.replace(/\n/g,' ').replace(/\r/g,' ');
because diferents SO use diferents ways to set a "new line", for example: Mac Unix Windows, after this, you can use other function to normalize white spaces.
Just use \\\n to replace it will work.
r.replace("\\\n"," ");
The solution from here worked perfect for me:
r.replace(/=(\r\n|\n|\r)/gm," ");
Related
This question already has answers here:
Regex for everything before last forward or backward slash
(3 answers)
Closed 5 years ago.
I have a list of filenames like
index.min.html
index.dev.html
index.min.js
index.dev.js
There.are.also.files.with.multiple.dots.and.other.extension
I want to cut off the extensions of the filenames, but the problem is that I can only use match for this task.
I tried many regular expressions looking like "index.min.html".match( /^((?!:(\.[^\.]+$)).+)/gi ); to select the filename without the last dot and extension, but they selected either the hole filename, nothing or the part before the first dot. Is there a way to select only the filename without extension?
Why regex? Simple substring expressions make this a lot simpler:
var filename = 'index.something.js.html';
alert(filename.substr(0, filename.lastIndexOf(".")));
I'd go for
/(.+)\..+$/mi
demo # regex101
See the demo, especially the matches. It only gives you the filename without the last . and the characters afterwards.
How about this one: (.*)\.[^\.]+
See http://regex101.com/r/xI6qM0
A simpler solution would be to just slice off the last element:
var a = "index.min.html";
var b = a.split('.').slice(0, -1).join('.');
Or, even better, using JavaScript's String function substr:
var b = a.substr(0, a.lastIndexOf("."));
Why do you have to use match?
Could do the trick, too:
function baseName(str) {
if (typeof str !== 'string') return;
var frags = str.split('.')
return frags.splice(0,frags.length-1).join('.');
}
Repl:http://repl.it/OvI
jsPerf: http://jsperf.com/string-extension-splits
Result:
substr is the fastest of all options in this thread. Kudos to the other guys.
I found this snippet somewhere and it works like a charm:
var n = parseInt(e.find("span.favNum").text().replace(/./g, "")) + 1;
If I do it in a similar way it doesn't work anymore.
I do the following:
<div id ="test">6.987</div>
var test = $("#test");
var r = test.text().replace(/./g, "");
console.log("wrong ", r);
I know that I can replace it also like this:
var r = test.text().replace(".", "");
This works.
I would like to understand why the "stolen" snippet is working.
Any idea?
http://jsfiddle.net/nJZMf/3/
The original script is found here: http://wp-svbtle.themeskult.com/
You will find the snippet by viewing the source of index.html and searching for .replace.
You need to escape the "."
test.text().replace(/\./g, "");
The reason that the code in the page you linked to works, where yours doesn't, is that it's not the same regular expression. Here's what I found in that page (and similar code in several places)
r = n.text().replace( /,/g, "" )
where r is a jQuery object.
Note that the regular expression has a , inside the //, not a . like the code you had trouble with.
Comma is not a special character in regular expressions, so it needs no special treatment. Period has a special meaning. As the other answers pointed out, it matches all characters, and you need to prefix it with \ if you want to match . only.
Also note that .replace() is not jQuery code, it's JavaScript.
jQuery's .text() method returns a JavaScript String value. So anything you do with that string - such as the .replace() call - is actually a JavaScript String method.
The distinction is important when you want to research a problem: a search for "javascript string replace" will get you better information than "jquery replace".
It has to be var r = test.text().replace(/\./g, ""); instead of var r = test.text().replace(/./g, ""); because you need to escape the . in order for it to be replaced.
http://jsfiddle.net/mrk1989/nJZMf/4/
Solution because I add \ in var r = test.text().replace(/\./g, "");
The problem was that you did not escape dot.
But keep in mind that:
.replace(".", "");
.replace(/\./g, "");
are two different things.
For example: https://jsfiddle.net/rmhpkz9n/1/
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
JavaScript Split without losing character
I have a string:
"<foo>abcdefg</bar><foo>abcdefg</bar><foo>abcdefg</bar><foo>abcdefg</bar>"
I want to separate all instances of "abcdefg" into an array like this:
["<foo>abcdefg</bar>", "<foo>abcdefg</bar>", "<foo>abcdefg</bar>", "<foo>abcdefg</bar>"];
I try:
var str="<foo>abcdefg</bar><foo>abcdefg</bar><foo>abcdefg</bar><foo>abcdefg</bar>";
var Array_Of_FooBars = str.split("</bar>");
alert(Array_Of_FooBars);
But it returns:
["<foo>abcdefg", "<foo>abcdefg", "<foo>abcdefg", "<foo>abcdefg",]
It is removing the separator ''. I don't want that.
How can I use split and not lose the separators from the string?
Thanks.
Ken
Try this. It's not a perfect solution, but it should work in most cases.
str.split(/(?=<foo>)/)
That is, split it in the position before each opening tag.
EDIT: You could also do it with match(), like so:
str.match(/<foo>.*?<\/bar>/g)
It seems that you would most likely want to use match:
var s = "<foo>abcd1efg</bar><foo>abc2defg</bar><foo>abc3defg</bar><foo>abc4defg</bar>"
s.match(/(<foo>.+?<\/bar>)/g)
// =>["<foo>abcd1efg</bar>", "<foo>abc2defg</bar>", "<foo>abc3defg</bar>", "<foo>abc4defg</bar>"]
You could just iterate over a simple regular expression and build the array that way:
var x = new RegExp('<foo>(.*?)</bar>', 'ig'),
s = "<foo>abcdefg</bar><foo>abcdefg</bar><foo>abcdefg</bar><foo>abcdefg</bar>",
matches = [];
while (i = x.exec(s)) {
matches.push(i[0]);
}
Just realized using String.match() would be better; this code would be more useful for matching the contents inside the tags.
Use positive lookahead so that the regular expression asserts that the special character exists, but does not actually match it:
string.split(/<br \/>(?=&#?[a-zA-Z0-9]+;)/g);
This question already has answers here:
How do I replace all occurrences of a string in JavaScript?
(78 answers)
Closed 6 years ago.
Hi I have a problem here. I am trying to replace all instances of + character in a string using javascript. What happens is that only the first instance is being changed.
Here is my code:
var keyword = "Hello+Word%+";
keyword = keyword.replace("+", encodeURIComponent("+"));
alert(keyword);
The output is Hello%2BWord%+ when it should be Hello%2BWord%%2B because there are 2 instances of +.
You can check this on : http://jsfiddle.net/Wy48Z/
Please help. Thanks in advance.
You need the global flag.
Fixed for you at http://jsfiddle.net/rtoal/Wy48Z/1/
var keyword = "Hello+Word%+";
keyword = keyword.replace(/\+/g, encodeURIComponent("+"));
alert(keyword);
The javascript regex, which is done by putting the expresison inbetween two forward slashes like: /<expression/
If you want to replace all, simply append a g after the last one like:
/<expression/g
In your case, it would be /\+/g
The cross-browser approach is to use a regexp with the g (global) flag, which means "process all matches of the pattern, not just the first":
keyword = keyword.replace(/\+/g, encodeURIComponent("+"));
Notice I prefix the plus sign with a backslash because it would otherwise have the special meaning of "match one or more of the preceding thing".
What would be a good way to do this. I have a string with lots of "<" and > and I want to replace them with < and >. So i wrote this:
var str = </text><word34212>
var p = str.replace('\<\;','\<');
var m = p.replace('\>\;','\>');
but that's just doing the first instance of each - and subsequent instances of </> are not replaced. I considered first counting the instances of the < and then looping and replacing one instance of the code on every iteration...and then doing the same for the > but obviously this is quite long-winded.
Can anyone suggest a neater way to do this?
To replace multiple occurances you use a regular expression, so that you can specify the global (g) flag:
var m = str.replace(/</g,'<').replace(/>/g,'>');
Taken from: http://www.bradino.com/javascript/string-replace/
The JavaScript function for String
Replace replaces the first occurrence
in the string. The function is similar
to the php function str_replace and
takes two simple parameters. The first
parameter is the pattern to find and
the second parameter is the string to
replace the pattern with when found.
The javascript function does not
Replace All...
To ReplaceAll you have to do it a
little differently. To replace all
occurrences in the string, use the g
modifier like this:
str = str.replace(/find/g,”replace”)
You need to use the global modifier:
var p = str.replace(/\<\;/g,'\<');
You need to use de /g modifier in your regex and it'll work. Check this page for an example : http://www.w3schools.com/jsref/jsref_replace.asp
I thing a associative array [regex -> replacement] and one iteration would do it