match only the last instance of a pattern with Javascript regexp - javascript

I want to remove size data from a file name like
var src = 'http://az648995.vo.msecnd.net/win/2015/11/Halo-1024x551.jpg';
src = src.replace(
/-\d+x\d+(.\S+)$/,
function( match, contents, offset, s ) {
return contents;
}
);
this works as expected and i get
http://az648995.vo.msecnd.net/win/2015/11/Halo.jpg
But if I have a filename like
http://az648995.vo.msecnd.net/win/2015/11/slot-Drake-08-2000x1000-1024x512.jpg
it returns
http://az648995.vo.msecnd.net/win/2015/11/slot-Drake-08-1024x512.jpg
instead of the desired
http://az648995.vo.msecnd.net/win/2015/11/slot-Drake-08-2000x1000.jpg

Your regex does not work as expected primarily because of an unescaped dot in (.\S+)$ part. An unescaped . matches any character but a newline. However, \S matches any non-whitespace, including a .. Besides unnecessary backtracking, you may get an unexpected result with a string like http://az648995.vo.msecnd.net/win/2015/11/slot-Drake-08-2000x1000-1024x512.MORE_TEXT_HERE.jpg.
Assuming the extension is the part of a string after the last dot, you can use
-\d+x\d+(\.[^.\s]+)$
See regex demo
The nagated character class [^.\s] matches any character but whitespace and a literal . symbol. Note that there is no point in using a callback function inside a replace, you can use a mere $1 backreference.
JS demo:
var src = 'http://az648995.vo.msecnd.net/win/2015/11/slot-Drake-08-2000x1000-1024x512.jpg';
src = src.replace(/-\d+x\d+(.[^.\s]+)$/, "$1");
document.body.innerHTML = src;

Try escaping the . and you will be fine:
/-\d+x\d+(\.\S+)$/

Slightly change the regex to be a little more explicit:
/-\d+x\d+(\.[^\s-]+)$/

The regex can be simplified to the following
Replace
-\d+x\d+(\.\S+)
With
$1

Related

Regex to get the text between two characters?

I want to replace a text after a forward slash and before a end parantheses excluding the characters.
My text:
<h3>notThisText/IWantToReplaceThis)<h3>
$('h3').text($('h3').text().replace(regEx, 'textReplaced'));
Wanted result after replace:
notThisText/textReplaced)
I have tried
regex = /([^\/]+$)+/ //replaces the parantheses as well
regex = \/([^\)]+) //replaces the slash as well
but as you can see in my comments neither of these excludes both the slash and the end parantheses. Can someone help?
A pattern like /(?<=\/)[^)]+(?=\))/ won't work in JS as its regex engine does not support a lookbehind construct. So, you should use one of the following solutions:
s.replace(/(\/)[^)]+(\))/, '$1textReplaced$2')
s.replace(/(\/)[^)]+(?=\))/, '$1textReplaced')
s.replace(/(\/)[^)]+/, '$1textReplaced')
s.replace(/\/[^)]+\)/, '/textReplaced)')
The (...) forms a capturing group that can be referenced to with $ + number, a backreference, from the replacement pattern. The first solution is consuming / and ), and puts them into capturing groups. If you need to match consecutive, overlapping matches, use the second solution (s.replace(/(\/)[^)]+(?=\))/, '$1textReplaced')). If the ) is not required at the end, the third solution (replace(/(\/)[^)]+/, '$1textReplaced')) will do. The last solution (s.replace(/\/[^)]+\)/, '/textReplaced)')) will work if the / and ) are static values known beforehand.
You can use str.split('/')
var text = 'notThisText/IWantToReplaceThis';
var splited = text.split('/');
splited[1] = 'yourDesireText';
var output = splited.join('/');
console.log(output);
Try Following: In your case startChar='/', endChar = ')', origString=$('h3').text()
function customReplace(startChar, endChar, origString, replaceWith){
var strArray = origString.split(startChar);
return strArray[0] + startChar + replaceWith + endChar;
}
First of all, you didn't define clearly what is the format of the text which you want to replace and the non-replacement part. For example,
Does notThisText contain any slash /?
Does IWantToReplaceThis contain any parentheses )?
Since there are too many uncertainties, the answer here only shows up the pattern exactly matches your example:
yourText.replace(/(\/).*?(\))/g, '$1textReplaced$2')
var text = "notThisText/IWantToReplaceThis";
text = text.replace(/\/.*/, "/whatever");
output : "notThisText/whatever"`

how to replace all occurrence of string between two symbols?

I'm working with RegEx on Javascript and here is where I stuck.
I have a simple string like
<html><body><span style=3D"font-family:Verdana; color:#000; font-size:10pt;=
"><div><font face=3D"verdana, geneva" size=3D"2">http://72.55.146.142:8880/=
order003.png.zip,120</body></html>
all i need to do is write javascript which can replace all strings in with "<" and ">" symbol.
I wrote something like this -
var strReplaceAll = Body;
var intIndexOfMatch = strReplaceAll.indexOf( "<" );
while (intIndexOfMatch != -1){
strReplaceAll = strReplaceAll.replace(/<.*>/,'')
intIndexOfMatch = strReplaceAll.indexOf( "<" );
}
but the problem is if body contains -
test<abc>test2<adg>
it will give me -
test
only or if body contains like -
<html>test<abc>test2<adg>
it will give me nothing please let me know how i can get-
testtest2
as a final output.
Try this regex instead:
<[^>]+>
DEMO:
http://regex101.com/r/kI5cJ7/2
DISCUSSION
Put the html code in a string and apply to this string the regex.
var htmlCode = ...;
htmlCode = htmlCode.replace(/<[^>]+>/g, '');
The original regex take too much characters (* is a greedy operator).
Check this page about Repetition with Star and Plus, especially the part on "Watch Out for The Greediness!".
Most people new to regular expressions will attempt to use <.+>. They will be surprised when they test it on a string like This is a <EM>first</EM> test. You might expect the regex to match <EM> and when continuing after that match, </EM>.
But it does not. The regex will match <EM>first</EM>. Obviously not what we wanted.
/(<.*?>)/
Just use this. Replace all the occurrences with "".
See demo.

How to remove the special characters from a string using javascript

I have the below String value to be displayed in text area and i want to remove the first characters ##*n|n from the string .
The string is as follows :
Symbol-001
##*n|nClaimant Name
##*n|nTransaction
I have used the below code to deal with removing the special characters
var paramVal1 = parent.noteText; //paramVal1 will have the string now
var pattern = /[##*n|n]/g;
var paramVal1 = paramVal1.replace(pattern,'');
document.getElementById("txtNoteArea").value = paramval1;//appending the refined string to text area
For the above used code am getting the out put string as below
Symbol-001
|Claimat Name //here 'n' is missing and i have an extra '|' character
|Transactio //'n' is missing here too and an extra '|' character
Kindly help to remove the characters ##*n|n without affecting the other values
What your regex is saying is "remove any of the following characters: #|*n". Clearly this isn't what you want!
Try this instead: /##\*n\|n/g
This says "remove the literal string ##*n|n". The backslashes remove the special meaning from * and |.
You are using regular expression reserved chars in your pattern, you need to escape them
You can use this expression:
var pattern = /[\#\#\*n\|n]/g;
i think use this /[##*n\|n]/g regEx
If you want to replace the first occurrence as you say on your question, you don't need to use regex. A simple string will do, as long as you escape the asterisk:
var str = "Symbol-001 ##*n|nClaimant Name ##*n|nTransaction";
var str2 = str.replace("##\*n|n", ""); //output: "Symbol-001 Claimant Name ##*n|nTransaction"
If you want to replace all the occurrences, you can use regex, escaping all the characters that have a special meaning:
var str3 = str.replace(/\#\#\*n\|n/g, ""); //output: "Symbol-001 Claimant Name Transaction"
Have a look at this regex builder, might come in handy - http://gskinner.com/RegExr/

Replace single backslash "\" with double backslashes "\\"

I have string with file path. I want to replace all single backslashes ("\") with double backslashes ("\\").
var replaceableString = "c:\asd\flkj\klsd\ffjkl";
var part = /#"\\"/g;
var filePath = replaceableString .replace(part, /#"\\"/);
console.log(filePath);
Console showed me it.
c:asdlkjklsdfjkl
I found something like this, unfortunately it didn't work.
Replacing \ with \\
Try:
var parts = replaceableString.split('\\');
var output = parts.join('\\\\');
Personally, as I am not so expert in reg exps, I tend to avoid them when dealing with non-alphanumeric characters, both due to readability and to avoid weird mistake.
var replaceableString = "c:\asd\flkj\klsd\ffjkl";
alert(replaceableString);
This will alert you c:asdlkjklsdfjkl because '\' is an escape character which will not be considered.
To have a backslash in your string , you should do something like this..
var replaceableString = "c:\\asd\\flkj\\klsd\\ffjkl";
alert(replaceableString);
This will alert you c:\asd\flkj\klsd\ffjkl
JS Fiddle
Learn about Escape sequences here
If you want your string to have '\' by default , you should escape it .. Use escape() function
var replaceableString = escape("c:\asd\flkj\klsd\ffjkl");
alert(replaceableString);
JS Fiddle
You have several problems in your code.
To get a \ in your string variable you need to escape it.
When you create a string like this: replaceableString = "c:\asd\flkj\klsd\ffjkl"; characters with a \ before are treated as escape sequences. So during the string creation, it tries to interpret the escape sequence \a, since this is not valid it stores the a to the string. E.g. \n would have been interpreted as newline.
I assume the # is coming from a .net example. Javascript does not know "raw" strings.
remove the quotes from your regex.
This would do what you want:
var string = "c:\\asd\\flkj\\klsd\\ffjkl";
var regex = /\\/g;
var FilePath = string.replace(regex, "\\\\");
Here is the answer:
For replacing single backslash with single forward slash:
var stringReplaced = String.raw`c:\asd\flkj\klsd\ffjkl`.split('\\').join('/')
console.log(stringReplaced);
For replacing double backslash with single forward slash:
var stringReplaced = String.raw`c:\\asd\\flkj\\klsd\\ffjkl`.split('\\\\').join('/')
console.log(stringReplaced);
\ is a escape character. Therefore replaceableString does not contain any backslashes.
To fix this you should declare the string like this:
var replaceableString = "c:\\asd\\flkj\\klsd\\ffjkl";
First encode the string
then replace all occurrences of %5C with %5C%5C
At the end decode the string
var result = encodeURI(input);
result=decodeURI(result.replace(/%5C/g,"%5C%5C"));
If you have no control over the contents of the string you are trying to find backslashes in, and it contains SINGLE \ values (eg. variable myPath contains C:\Some\Folder\file.jpg), then you can actually reference the single backslashes in JavaScript as String.fromCharCode(92).
So to get the file name in my filepath example above.
var justTheName = myPath.split(String.fromCharCode(92)).pop();
In case of string matching, it is better to use encodeURIComponent, decodeURIComponent.
match(encodeURIComponent(inputString));
function match(input)
{
for(i=0; i<arr.length; i++)
{
if(arr[i] == decodeURIComponent(input))
return true;
else return false;
}
}
In the case of a single back slash in the string, the javascript replace method did not allow me to replace the single back slash.
Instead I had to use the split method which returns an array of the split strings and then concatenate the strings without the back slash (or whatever you want to replace it with)
Solution (replaced backslash with underscore):
var splitText = stringWithBackslash.split('\\');
var updatedText = splitText[0] + '_' + splitText[1];
You need to pass to pass value of a string through String.raw before you assign value to a variable.
var replaceableString = String.raw`c:\asd\flkj\klsd\ffjkl`.replace(/\\/g,"\\\\");
console.log(replaceableString)

Replace Characters from string with javascript

I have a string like (which is a shared path)
\\cnyc12p20005c\mkt$\\XYZ\
I need to replace all \\ with single slash so that I can display it in textbox. Since it's a shared path the starting \\ should not be removed. All others can be removed.
How can I achieve this in JavaScript?
You could do it like this:
var newStr = str.replace(/(.)\\{2}/, "$1\\");
Or this, if you don't like having boobs in your code:
var newStr = "\\" + str.split(/\\{1,2}/).join("\\");
You can use regular expression to achieve this:
var s = '\\\\cnyc12p20005c\\mkt$\\\\XYZ\\';
console.log(s.replace(/.\\\\/g, '\\')); //will output \\cnyc12p20005c\mkt$\XYZ\
Double backslashes are used because backslash is special character and need to be escaped.

Categories