How to replace all newlines after reading a file - javascript

How can I replace a newline in a string with a ','? I have a string that is read from a file:
const fileText = (<FileReader>fileLoadedEvent.target).result.toString();
file.readCSV(fileText);
It takes a string from a file:
a,b,c,d,e,f
,,,,,
g,h,i,j,k,l
I'm able to detect the newline with this:
if (char === '\n')
But replacing \n like this doesn't work
str = csvString.replace('/\n/g');
I want to get the string to look like this:
a,b,c,d,e,f,
,,,,,,
g,h,i,j,k,l,

You can add , at end of each line like this
$ - Matches end of line
let str = `a,b,c,d,e,f
,,,,,
g,h,i,j,k,l`
let op = str.replace(/$/mg, "$&"+ ',')
console.log(op)

Try replacing the pattern $ with ,, comma:
var input = 'a,b,c,d,e,f';
input = input.replace(/$/mg, ",");
console.log(input);
Since you intend to retain the newlines/carriage returns, we can just take advantage of $ to represent the end of each line.

let text = `a,b,c,d,e,f
,,,,,
g,h,i,j,k,l`;
let edited = text.replace(/\s+/g, '');
console.log( edited )
You can try this solution also. \s means white spaces.

You may try out like,
// Let us have some sentences havin linebreaks as \n.
let statements = " Programming is so cool. \n We love to code. \n We can built what we want. \n :)";
// We will console it and see that they are working fine.
console.log(statements);
// We may replace the string via various methods which are as follows,
// FIRST IS USING SPLIT AND JOIN
let statementsWithComma1 = statements.split("\n").join(",");
// RESULT
console.log("RESULT1 : ", statementsWithComma1);
// SECOND IS USING REGEX
let statementsWithComma2 = statements.replace(/\n/gi, ',');
// RESULT
console.log("RESULT2 : ", statementsWithComma2);
// THIRS IS USING FOR LOOP
let statementsWithComma3 = "";
for(let i=0; i < statements.length; i++){
if(statements[i] === "\n")
statementsWithComma3 += ','
else
statementsWithComma3 += statements[i]
}
// RESULT
console.log("RESULT3 : ", statementsWithComma3);

I believe in some systems newline is \r\n or just \r, so give /\r?\n|\r/ a shot

Related

How to replace numbers with an empty char

i need to replace phone number in string on \n new line.
My string: Jhony Jhons,jhon#gmail.com,380967574366
I tried this:
var str = 'Jhony Jhons,jhon#gmail.com,380967574366'
var regex = /[0-9]/g;
var rec = str.trim().replace(regex, '\n').split(','); //Jhony Jhons,jhon#gmail.com,
Number replace on \n but after using e-mail extra comma is in the string need to remove it.
Finally my string should look like this:
Jhony Jhons,jhon#gmail.com\n
You can try this:
var str = 'Jhony Jhons,jhon#gmail.com,380967574366';
var regex = /,[0-9]+/g;
str.replace(regex, '\n');
The snippet above may output what you want, i.e. Jhony Jhons,jhon#gmail.com\n
There's a lot of ways to that, and this is so easy, so try this simple answer:-
var str = 'Jhony Jhons,jhon#gmail.com,380967574366';
var splitted = str.split(","); //split them by comma
splitted.pop(); //removes the last element
var rec = splitted.join() + '\n'; //join them
You need a regex to select the complete phone number and also the preceding comma. Your current regex selects each digit and replaces each one with an "\n", resulting in a lot of "\n" in the result. Also the regex does not match the comma.
Use the following regex:
var str = 'Jhony Jhons,jhon#gmail.com,380967574366'
var regex = /,[0-9]+$/;
// it replaces all consecutive digits with the condition at least one digit exists (the "[0-9]+" part)
// placed at the end of the string (the "$" part)
// and also the digits must be preceded by a comma (the "," part in the beginning);
// also no need for global flag (/g) because of the $ symbol (the end of the string) which can be matched only once
var rec = str.trim().replace(regex, '\n'); //the result will be this string: Jhony Jhons,jhon#gmail.com\n
var str = "Jhony Jhons,jhon#gmail.com,380967574366";
var result = str.replace(/,\d+/g,'\\n');
console.log(result)

Javascript regex to add to every character of a string a backslash

So as the title says I'd like to add to every character of a string a backslash, whether the string has special characters or not. The string should not be considered 'safe'
eg:
let str = 'dj%^3&something';
str = str.replace(x, y);
// str = '\d\j\%\^\3\&\s\o\m\e\t\h\i\n\g'
You could capture every character in the string with (.) and use \\$1 as replacement, I'm not an expert but basically \\ will render to \ and $1 will render to whatever (.) captures.
HIH
EDIT
please refer to Wiktor Stribiżew's comment for an alternative which will require less coding. Changes as follows:
str = str.replace(/(.)/g, '\\$1'); for str = str.replace(/./g, '\\$&');
Also, for future reference I strongly advice you to visit regexr.com when it comes to regular expressions, it's helped ME a lot
let str = 'dj%^3&something';
str = str.replace(/(.)/g, '\\$1');
console.log(str);
If you just want to display a string safely, you should just do:
let str = 'dj%^3&something';
let node = document.createTextNode(str);
let dest = document.querySelector('.whatever');
dest.appendChild(node);
And then you are guaranteed that it will be treated as text, and won't be able to execute a script or anything.
For example: https://jsfiddle.net/s6udj03L/1/
You can split the string to an array, add a \ to each element to the array, then joint the array back to the string that you wanted.
var str = 'dj%^3&something';
var split = str.split(""); // split string into array
for (var i = 0; i < split.length; i++) {
split[i] = '\\' + split[i]; // add backslash to each element in array
}
var joint = split.join('') // joint array to string
console.log(joint);
If you don't care about creating a new string and don't really have to use a regex, why not just iterate over the existing one and place a \ before each char. Notice to you have to put \\ to escape the first \.
To consider it safe, you have to encode it somehow. You could replace typical 'non-safe' characters like in the encode() function below. Notice how & get's replaced by &
let str = 'dj%^3&something';
let out = "";
for(var i = 0; i < str.length; i++) {
out += ("\\" + str[i]);
}
console.log(out);
console.log(encode(out));
function encode(string) {
return String(string).replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>').replace(/"/g, '"');
}

Regex match cookie value and remove hyphens

I'm trying to extract out a group of words from a larger string/cookie that are separated by hyphens. I would like to replace the hyphens with a space and set to a variable. Javascript or jQuery.
As an example, the larger string has a name and value like this within it:
facility=34222%7CConner-Department-Store;
(notice the leading "C")
So first, I need to match()/find facility=34222%7CConner-Department-Store; with regex. Then break it down to "Conner Department Store"
var cookie = document.cookie;
var facilityValue = cookie.match( REGEX ); ??
var test = "store=874635%7Csomethingelse;facility=34222%7CConner-Department-Store;store=874635%7Csomethingelse;";
var test2 = test.replace(/^(.*)facility=([^;]+)(.*)$/, function(matchedString, match1, match2, match3){
return decodeURIComponent(match2);
});
console.log( test2 );
console.log( test2.split('|')[1].replace(/[-]/g, ' ') );
If I understood it correctly, you want to make a phrase by getting all the words between hyphens and disallowing two successive Uppercase letters in a word, so I'd prefer using Regex in that case.
This is a Regex solution, that works dynamically with any cookies in the same format and extract the wanted sentence from it:
var matches = str.match(/([A-Z][a-z]+)-?/g);
console.log(matches.map(function(m) {
return m.replace('-', '');
}).join(" "));
Demo:
var str = "facility=34222%7CConner-Department-Store;";
var matches = str.match(/([A-Z][a-z]+)-?/g);
console.log(matches.map(function(m) {
return m.replace('-', '');
}).join(" "));
Explanation:
Use this Regex (/([A-Z][a-z]+)-?/g to match the words between -.
Replace any - occurence in the matched words.
Then just join these matches array with white space.
Ok,
first, you should decode this string as follows:
var str = "facility=34222%7CConner-Department-Store;"
var decoded = decodeURIComponent(str);
// decoded = "facility=34222|Conner-Department-Store;"
Then you have multiple possibilities to split up this string.
The easiest way is to use substring()
var solution1 = decoded.substring(decoded.indexOf('|') + 1, decoded.length)
// solution1 = "Conner-Department-Store;"
solution1 = solution1.replace('-', ' ');
// solution1 = "Conner Department Store;"
As you can see, substring(arg1, arg2) returns the string, starting at index arg1 and ending at index arg2. See Full Documentation here
If you want to cut the last ; just set decoded.length - 1 as arg2 in the snippet above.
decoded.substring(decoded.indexOf('|') + 1, decoded.length - 1)
//returns "Conner-Department-Store"
or all above in just one line:
decoded.substring(decoded.indexOf('|') + 1, decoded.length - 1).replace('-', ' ')
If you want still to use a regular Expression to retrieve (perhaps more) data out of the string, you could use something similar to this snippet:
var solution2 = "";
var regEx= /([A-Za-z]*)=([0-9]*)\|(\S[^:\/?#\[\]\#\;\,']*)/;
if (regEx.test(decoded)) {
solution2 = decoded.match(regEx);
/* returns
[0:"facility=34222|Conner-Department-Store",
1:"facility",
2:"34222",
3:"Conner-Department-Store",
index:0,
input:"facility=34222|Conner-Department-Store;"
length:4] */
solution2 = solution2[3].replace('-', ' ');
// "Conner Department Store"
}
I have applied some rules for the regex to work, feel free to modify them according your needs.
facility can be any Word built with alphabetical characters lower and uppercase (no other chars) at any length
= needs to be the char =
34222 can be any number but no other characters
| needs to be the char |
Conner-Department-Store can be any characters except one of the following (reserved delimiters): :/?#[]#;,'
Hope this helps :)
edit: to find only the part
facility=34222%7CConner-Department-Store; just modify the regex to
match facility= instead of ([A-z]*)=:
/(facility)=([0-9]*)\|(\S[^:\/?#\[\]\#\;\,']*)/
You can use cookies.js, a mini framework from MDN (Mozilla Developer Network).
Simply include the cookies.js file in your application, and write:
docCookies.getItem("Connor Department Store");

Removing last comma

I read content from a file and then write it another file after editing . While editing , for each read line i put a comma at the end of line and then write it to the file. For the last read line i do not want to write a comma. How should i do it.?
while(!inputFile.AtEndOfStream){
var readLine = inputFile.ReadLine();
var omitChars = new RegExp("#define").test(readLine);
if(omitChars==1){
var stringReadPosition = readLine.substr(8);
var finalString = stringReadPosition.replace(/\s+/g, ': ');
asd = outputFile.Write(finalString.replace(/^(_)/, "") + ",\r\n");
}
}
outputFile.Write("};\r\n");
inputFile.Close();
outputFile.Close();
}
You can use substring in order to remove the last character of the string after you have formed the string:
finalString = finalString.substring(0, finalString.length - 1);
An alternative would be the use of slice, taking into consideration that negative indices are relative to the end of the string:
finalString = finalString.slice(0,-1);
Take a look in this question for more.
UPDATE: For your case, you could check whether or not you have reached the EOF - meaning you have read the last line, and then apply slice or substring:
//....
var stringReadPosition = readLine.substr(8);
var finalString = stringReadPosition.replace(/\s+/g, ': ');
//Check if stream reached EOF.
if(inputFile.AtEndOfStream) {
finalString = finalString.slice(0,-1);
}
asd = outputFile.Write(finalString.replace(/^(_)/, "") + ",\r\n");
//....
try this asd = asd.replace(/,\s*$/, "");
this will remove last comma, I have tried this, its working .Check if it works in ur code.
Try this code inside while loop

Javascript Remove strings in beginning and end

base on the following string
...here..
..there...
.their.here.
How can i remove the . on the beginning and end of string like the trim that removes all spaces, using javascript
the output should be
here
there
their.here
These are the reasons why the RegEx for this task is /(^\.+|\.+$)/mg:
Inside /()/ is where you write the pattern of the substring you want to find in the string:
/(ol)/ This will find the substring ol in the string.
var x = "colt".replace(/(ol)/, 'a'); will give you x == "cat";
The ^\.+|\.+$ in /()/ is separated into 2 parts by the symbol | [means or]
^\.+ and \.+$
^\.+ means to find as many . as possible at the start.
^ means at the start; \ is to escape the character; adding + behind a character means to match any string containing one or more that character
\.+$ means to find as many . as possible at the end.
$ means at the end.
The m behind /()/ is used to specify that if the string has newline or carriage return characters, the ^ and $ operators will now match against a newline boundary, instead of a string boundary.
The g behind /()/ is used to perform a global match: so it find all matches rather than stopping after the first match.
To learn more about RegEx you can check out this guide.
Try to use the following regex
var text = '...here..\n..there...\n.their.here.';
var replaced = text.replace(/(^\.+|\.+$)/mg, '');
Here is working Demo
Use Regex /(^\.+|\.+$)/mg
^ represent at start
\.+ one or many full stops
$ represents at end
so:
var text = '...here..\n..there...\n.their.here.';
alert(text.replace(/(^\.+|\.+$)/mg, ''));
Here is an non regular expression answer which utilizes String.prototype
String.prototype.strim = function(needle){
var first_pos = 0;
var last_pos = this.length-1;
//find first non needle char position
for(var i = 0; i<this.length;i++){
if(this.charAt(i) !== needle){
first_pos = (i == 0? 0:i);
break;
}
}
//find last non needle char position
for(var i = this.length-1; i>0;i--){
if(this.charAt(i) !== needle){
last_pos = (i == this.length? this.length:i+1);
break;
}
}
return this.substring(first_pos,last_pos);
}
alert("...here..".strim('.'));
alert("..there...".strim('.'))
alert(".their.here.".strim('.'))
alert("hereagain..".strim('.'))
and see it working here : http://jsfiddle.net/cettox/VQPbp/
Slightly more code-golfy, if not readable, non-regexp prototype extension:
String.prototype.strim = function(needle) {
var out = this;
while (0 === out.indexOf(needle))
out = out.substr(needle.length);
while (out.length === out.lastIndexOf(needle) + needle.length)
out = out.slice(0,out.length-needle.length);
return out;
}
var spam = "this is a string that ends with thisthis";
alert("#" + spam.strim("this") + "#");
Fiddle-ige
Use RegEx with javaScript Replace
var res = s.replace(/(^\.+|\.+$)/mg, '');
We can use replace() method to remove the unwanted string in a string
Example:
var str = '<pre>I'm big fan of Stackoverflow</pre>'
str.replace(/<pre>/g, '').replace(/<\/pre>/g, '')
console.log(str)
output:
Check rules on RULES blotter

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