A few days ago I posted a similar question, but I do not quite understand the principle. Are there good resources where the replace function combined with regular expressions is explained?
Anyways, right now I have the following problem: A string which starts with # should be placed in an link. So #test should be replaced to #test .
Also, these rules should apply:
The string can only contain one #, which is at the beginning.
If there are more strings, also replace them. I thought you can do this by putting /g behind the regex?
This is what I have so far:
value = "is #test";
var text = value.replace(/^.*(#)(\w+).*$/, "<a href='$2'>$1$2</a>");
My output
#test
EDIT:
The link is now working. However, the word "is" is missing.
You need to capture the ambient text:
value = "is #test or what";
var text = value.replace(/^(.*)#(\w+)(.*)$/, "$1<a href='$2'>#$2</a>$3");
Or just capture less:
var text = value.replace(/#(\w+)/, "<a href='$1'>#$1</a>");
When performing a .replace(), you need to include all the characters in the RegExp that you wish to replace, preserving the ones you want to keep with parentheses.
var test = 'is #test';
function makeAt(string){
return string.replace(/^.*(#)(\w+).*$/, "<a href='$2'>$1$2</a>");
}
console.log(makeAt(test));
Related
I am trying to match everything after (but not including!) the last occurrence of a string in JavaScript.
The search, for example, is:
[quote="user1"]this is the first quote[/quote]\n[quote="user2"]this is the 2nd quote and some url https://www.google.com/[/quote]\nThis is all the text I\'m wirting about myself.\n\nLook at me ma. Javascript.
Edit: I'm looking to match everything after the last quote block. So I was trying to match everything after the last occurrence of "quote]" ? Idk if this is the best solution but its what i've been trying.
I'll be honest, i suck at this Regex stuff.. here is what i've been trying with the results..
regex = /(quote\].+)(.*)/ig; // Returns null
regex = /.+((quote\]).+)$/ig // Returns null
regex = /( .* (quote\]) .*)$/ig // Returns null
I have made a JSfiddle for anyone to have a play with here:
https://jsfiddle.net/au4bpk0e/
One option would be to match everything up until the last [/quote], and then get anything following it. (example)
/.*\[\/quote\](.*)$/i
This works since .* is inherently greedy, and it will match every up until the last \[\/quote\].
Based on the string you provided, this would be the first capturing group match:
\nThis is all the text I\'m wirting about myself.\n\nLook at me ma. Javascript.
But since your string contains new lines, and . doesn't match newlines, you could use [\s\S] in place of . in order to match anything.
Updated Example
/[\s\S]*\[\/quote\]([\s\S]*)$/i
You could also avoid regex and use the .lastIndexOf() method along with .slice():
Updated Example
var match = '[\/quote]';
var textAfterLastQuote = str.slice(str.lastIndexOf(match) + match.length);
document.getElementById('res').innerHTML = "Results: " + textAfterLastQuote;
Alternatively, you could also use .split() and then get the last value in the array:
Updated Example
var textAfterLastQuote = str.split('[\/quote]').pop();
document.getElementById('res').innerHTML = "Results: " + textAfterLastQuote;
I am using regular expressions to do some basic converting of wiki markup code into copy-pastable plain text, and I'm using javascript to do the work.
However, javascript's regex engine behaves much differently to the ones I've used previously as well as the regex in Notepad++ that I use on a daily basis.
For example- given a test string:
==Section Header==
===Subsection 1===
# Content begins here.
## Content continues here.
I want to end up with:
Section Header
Subsection 1
# Content begins here.
## Content continues here.
Simply remove all equals signs.
I began with the regex setup of:
var reg_titles = /(^)(=+)(.+)(=+)/
This regex searches for lines that begin with one or more equals with another set of one or more equals. Rubular shows that it matches my lines accurately and does not catch equals signs in the middle of contet. http://www.rubular.com/r/46PrkPx8OB
The code to replace the string based on regex
var lines = $('.tb_in').val().split('\n'); //use jquery to grab text in a textarea, and split into an array of lines based on the \n
for(var i = 0;i < lines.length;i++){
line_temp = lines[i].replace(reg_titles, "");
lines[i] = line_temp; //replace line with temp
}
$('.tb_out').val(lines.join("\n")); //rejoin and print result
My result is unfortunately:
Section Header==
Subsection 1===
# Content begins here.
## Content continues here.
I cannot figure out why the regex replace function, when it finds multiple matches, seems to only replace the first instance it finds, not all instances.
Even when my regex is updated to:
var reg_titles = /(={2,})/
"Find any two or more equals", the output is still identical. It makes a single replacement and ignores all other matches.
No one regex expression executor behaves this way for me. Running the same replace multiple times has no effect.
Any advice on how to get my string replace function to replace ALL instances of the matched regex instead of just the first one?
^=+|=+$
You can use this.Do not forget to add g and m flags.Replace by ``.See demo.
http://regex101.com/r/nA6hN9/28
Add the g modifier to do a global search:
var reg_titles = /^(=+)(.+?)(=+)/g
Your regex is needlessly complex, and yet doesn't actually accomplish what you set out to do. :) You might try something like this instead:
var reg_titles = /^=+(.+?)=+$/;
lines = $('.tb_in').val().split('\n');
lines.forEach(function(v, i, a) {
a[i] = v.replace(reg_titles, '$1');
})
$('.tb_out').val(lines.join("\n"));
I've searched Hi and low, but couldn't find an exact answer to what i'm trying to do...
I'd like to find any text with __ in the beginning and /__ at the end (i.e. "in the middle of the sentence __this/__ could be underlined, and __this(!) can also/__ be underlined"). so, it can be one word, or a few, with any characters in there, including spaces. There could be different words and combination - in the same paragraph - starting with __ and ending with /__ .
Once found, i'd like to remove the __ and /__ and replace them with HTML - for example, a div tag.
so:
__sample string /__
should be:
<div>sample string</div>
I know i'm supposed to use capturing groups, but i can't find a way to do this.
javascript:
.match seems to match, and put the results in an array - but how do i go back into the string and replace the found results?
jquery:
.replace should work for this, but i'm not sure how to reference the found string, and surround it...
Thanks for reading!
You don't need match but you need String#replace:
s='in the middle of the sentence __this/__ could be underlined, and __this(!) can also/__ be underlined';
var repl = s.replace(/__(.*?)\/__/g, "<div>$1</div>");
//=> in the middle of the sentence <div>this</div> could be underlined, and <div>this(!) can also</div> be underlined
Try this. It's a slight variation of something we have working here. I modified the replace part...but didn't actually test it. If you need to find more than one occurrence, I suppose you could pass-in a new starting index which would be the index of where you left off from the first time.
public static string getBetween(string strSource, string strStart, string strEnd)
{
int Start, End;
if (strSource.Contains(strStart) && strSource.Contains(strEnd))
{
Start = strSource.IndexOf(strStart, 0) + strStart.Length;
End = strSource.IndexOf(strEnd, Start);
return strSource.Substring(Start, End - Start);
}
else
{
return "";
}
}
string betweenString = getBetween(sourceString, "__", "/__");
sourceString = sourceString.Replace("__"+betweenString+"/__", "<div>"+betweenString+"</div>");
I have a JS stirng like this
<div id="grouplogo_nav"><br> <ul><br> <li><a class="group_hlfppt" target="_blank" href="http://www.hlfppt.org/"> </a></li><br> </ul><br> </div>
I need to remove all <br> and $nbsp; that are only between > and <. I tried to write a regular expression, but didn't got it right. Does anybody have a solution.
EDIT :
Please note i want to remove only the tags b/w > and <
Avoid using regex on html!
Try creating a temporary div from the string, and using the DOM to remove any br tags from it. This is much more robust than parsing html with regex, which can be harmful to your health:
var tempDiv = document.createElement('div');
tempDiv.innerHTML = mystringwithBRin;
var nodes = tempDiv.childNodes;
for(var nodeId=nodes.length-1; nodeId >= 0; --nodeId) {
if(nodes[nodeId].tagName === 'br') {
tempDiv.removeChild(nodes[nodeId]);
}
}
var newStr = tempDiv.innerHTML;
Note that we iterate in reverse over the child nodes so that the node IDs remain valid after removing a given child node.
http://jsfiddle.net/fxfrt/
myString = myString.replace(/^( |<br>)+/, '');
... where /.../ denotes a regular expression, ^ denotes start of string, ($nbsp;|<br>) denotes " or <br>", and + denotes "one or more occurrence of the previous expression". And then simply replace that full match with an empty string.
s.replace(/(>)(?: |<br>)+(\s?<)/g,'$1$2');
Don't use this in production. See the answer from Phil H.
Edit: I try to explain it a bit and hope my english is good enough.
Basically we have two different kinds of parentheses here. The first pair and third pair () are normal parentheses. They are used to remember the characters that are matched by the enclosed pattern and group the characters together. For the second pair, we don't need to remember the characters for later use, so we disable the "remember" functionality by using the form (?:) and only group the characters to make the + work as expected. The + quantifier means "one or more occurrences", so or <br> must be there one or more times. The last part (\s?<) matches a whitespace character (\s), which can be missing or occur one time (?), followed by the characters <. $1 and $2 are kind of variables that are replaces by the remembered characters of the first and third parentheses.
MDN provides a nice table, which explains all the special characters.
You need to replace globally. Also don't forget that you can have the being closed . Try this:
myString = myString.replace(/( |<br>|<br \/>)/g, '');
This worked for me, please note for the multi lines
myString = myString.replace(/( |<br>|<br \/>)/gm, '');
myString = myString.replace(/^( |<br>)+/, '');
hope this helps
My text looks similar to this:
action=addItem&siteId=4&lang_locale=en_US&country=US&catalogId=1&productId=417689&displaySize=7&skuSize=2194171&qty=1&pil=7&psh=had+AIRJRnjbp7+rGivIKg00
and I want to replace the value of 'psh'. It may sometimes not be the last value (it may be followed by &something=else).
I've tried doing these lines of code:
var text = text.replace(/&psh=.*(?=&|$)/, "&psh=" + data.psh);
var text = text.replace(/&psh=.*(?=[&|$]+)/, "&psh=" + data.psh);
var text = text.replace(/(?:&psh=)(.*)(?=[&|$]+)/, data.psh);
None of them work for both situations. Use this site to check regexes.
This should work:
var text = text.replace(/&psh=[^&]*/, "&psh=" + data.psh);
[^&]* matches a string of any length that consists of any characters except &, therefore the match will continue until the end of the string or until (but not including) the next &, whichever comes first.
Tim's answer may work, but I fear it is not the best possible answer. The string you are giving as an example looks a lot like a url. If it is, that means there can sometimes be a pound sign in it as well (#). To compensate for that you actually need to modify your code to look like this:
var text = text.replace(/&psh=[^&#]*/, "&psh=" + data.psh);
Notice the # which was added in order to not get tripped up by anchor tags in the url.