What is the best way to check the text area value for line breaks and then calculate the number of occurrences, if any?
I have a text area on a form on my webpage. I am using JavaScript to grab the value of the text area and then checking its length.
Example
enteredText = textareaVariableName.val();
characterCount = enteredText.length; // One line break entered returns 1
If a user enters a line break in the text area my calculation above gives the line break a length of 1. However I need to give line breaks a length of 2. Therefore I need to check for line breaks and the number of occurrences and then add this onto the total length.
Example of what I want to achieve
enteredText = textareaVariableName.val();
characterCount = enteredText.length + numberOfLineBreaks;
My solution before asking this question was the following:
enteredText = textareaVariableName.val();
enteredTextEncoded = escape(enteredText);
linebreaks = enteredTextEncoded.match(/%0A/g);
(linebreaks != null) ? numberOfLineBreaks = linebreaks.length : numberOfLineBreaks = 0;
I could see that encoding the text and checking for %0A was a bit long-winded, so I was after some better solutions. Thank you for all the suggestions.
You can use match on the string containing the line breaks, and the number of elements in that array should correspond to the number of line breaks.
enteredText = textareaVariableName.val();
numberOfLineBreaks = (enteredText.match(/\n/g)||[]).length;
characterCount = enteredText.length + numberOfLineBreaks;
/\n/g is a regular expression meaning 'look for the character \n (line break), and do it globally (across the whole string).
The ||[] part is just in case there are no line breaks. Match will return null, so we test the length of an empty array instead to avoid errors.
Here's one way:
var count = text.length + text.replace(/[^\n]/g, '').length;
Alternatively, you could replace all the "naked" \n characters with \r\n and then use the overall length.
I'd do this using a regular expression:
var inTxt = document.getElementById('txtAreaId').value;
var charCount = inTxt.length + inTxt.match(/\n/gm).length;
where /\n/ matches linebreaks (obviously), g is the global flag. m stands for mult-line, which you evidently need in this case...Alternatively, though as I recall this is a tad slower:
var charCount = inTxt.length + (inTxt.split("\n").length);
Edit
Just realized that, if no line breaks are matched, this will spit an error, so best do:
charCount = intTxt.length + (inTxt.match(/\n/) !== null ? inTxt.match(/\n/gm).length : 0);
Or something similar...
For new JS use encodeURI(), because escape() is deprecated in ECMAScript 1.5.
Instead use:
enteredText = textareaVariableName.val();
enteredTextEncoded = encodeURI(enteredText);
linebreaks = enteredTextEncoded.match(/%0A/g);
(linebreaks != null) ? numberOfLineBreaks = linebreaks.length : numberOfLineBreaks = 0;
You can split the text based on new lines:
let textArray = text.split(/^/gm)
console.log(textArray.length)
Related
I'm trying to get the first element of each line, be it either a number or a string but when the line starts with a number, my current attempt still includes it:
const totalWords = "===========\n\n 1-test\n\n 2-ests \n\n 1 zfzrf";
const firstWord = totalWords.replace(/\s.*/,'')
The output I get :
1-test
2-ests
1 zfzrf
The output I would like:
1
2
1
Alternatively, if you are interested in a non-regexp version (should be faster)
var str = "===========\n\n 1-test\n\n 2-ests \n\n 1 zfzrf";
var res = str.split("\n");
for (row of res) {
let words = row.trim().split(' ');
let firstWord = words[0].trim();
// get first character, parse to int, validate it is infact integer
let element = firstWord.charAt(0);
if (Number.isInteger(parseInt(element))) {
console.log('Row', row);
console.log('Element: ', element);
}
}
Your Regex should skip leading spaces and then capture everything until a space or a dash, so you might want to go with ^\s*([^ -]+).
(See https://regex101.com/r/u7ELiw/1 for application to your examples)
If you additionally know exactly that you are looking for a single digit, you can instead go for ^\s*(\d)
(See https://regex101.com/r/IWhEQ1/1 again for applications)
Maybe im not too sure what you are asking but why are you using something as convoluted as regex when
line.charAt(0)
works pretty well?
I have string content that gets delivered to me via TCP. This info is only relevant because it means that I do not consistently retrieve the same string. I have a <start> and <stop> separator to ensure that any time I get the data via TCP, I am outputting the full content.
My incoming content looks like so:
<start>Apple Bandana Cadillac<stop>
I want to get everything in between <start> and <stop>. So just Apple Bandana Cadillac.
My script to do this looks like so:
servercsv.on("connection", function(socket){
let d_basic = "";
socket.on('data', function(data){
d_basic += data.toString();
let d_csvindex = d_basic.indexOf('<stop>');
while (d_csvindex > -1){
try {
let strang = d_basic.substring(0, d_csvindex);
let dyson = strang.replace(/<start>/g, '');
let dson = papaparse.parse(dyson);
myfunction(dson);
}
catch(e){ console.log(e); }
d_basic = d_basic.substring(d_csvindex+1);
d_csvindex = d_basic.indexOf('<stop>');
}
});
});
What this means is that I am getting everything before the <stop> string and outputting it. I have also included the line let dyson = strang.replace(/<start>/g, ''); because I want to remove the <start> text.
However, because this is TCP, I am not guranteed to get all parts of this string. As a result, I frequently get back stop>Apple Bandana Cadillac<stop> or some variation of this (such as start>Apple Bandana Cadillac<stop>. It is not consistent enough that I can just do strang.replace("start>", "")
Ideally, I would like my separator to select content that is in between <start> and <stop>. Not just <stop>. However, I am unsure how to do so.
Alternatively, I can also settle for a regex that retrieves all combination of <start><stop> strings during my while loop, and just delete them. So check for <, s, t, a, r, t individually and so forth. But unsure how to implement regex to delete portions of a whole string.
Assuming you get full response:
var test = "<start>Apple Bandana Cadillac<stop>";
var testRE = test.match("<start>(.*)<stop>");
testRE[1] //"Apple Bandana Cadillac"
If there are new lines between <start> and <stop>
var test = "<start>Apple Bandana Cadillac<stop>";
var testRE = test.match("<start>([\\S\\s]*)<stop>");
testRE[1] //"Apple Bandana Cadillac"
Using regular expressions capturing group here.
Try this regex with replace() method:
/<st.*?>(.*?)(?!<st)/g
Literal.................................................: <st
Any char zero or more times lazily...: .*?
Literal..................................................: >
Begin capture group..........................: (
Any char zero or more times lazily...: .*?
End capture group.............................: )
Begin negative lookahead.................: (?!
Literal...................................................: <st
End negative lookahead....................: )
In the Demo below notice that the test example consists of multiple lines, and variances of <start> and <stop> (basically <st).
Demo 1
var rgx = /<st.*?>(.*?)(?!<st)/g;
var str = `<start>Apple Bandana Cadillac<stop>
<stop>Grapes Trampoline Ham<stop>
<start>Kebab Matador Pencil<start>`;
var res = str.replace(rgx, `$1`);
console.log(res);
Update
"say I have op>Grapes Trampoline Ham<stop>...still trying to remove all parts of the string <stop>"
/^(.*?>)(.*?)(<.*?)$/gm;
A simple explanation will have to do since a step-by-step such as Demo 1 would take too much time.
This RegEx is multiline. /m
^..........Begin line.
(.*?>)..Lazily capture everything until literal >........[Return as $1]
(.*?)...Then lazily capture everything until................[Return as $2]
(<.*?)..Literal < and lazily capture everything until..[Return as $3]
$...........End line.
The trick is to replace the second capture $2 and leave $1 and $3 alone.
Demo 2
var rgx = /^(.*?>)(.*?)(<.*?)$/gm;
var str = `<start>Apple Bandana Cadillac<stop>
<stop>Grapes Trampoline Ham<stop>
<start>Kebab Matador Pencil<start>
op>Score False Razor<stop>
`;
var res = str.replace(rgx, `$2`);
console.log(res);
so my idea is like this..
var songList = ["1. somesong.mid","13. abcdef.mid","153. acde.mid"];
var newString = myString.substr(4); // i want this to dynamically trim the numbers till it has reached the .
// but i wanted the 1. 13. 153. and so on removed.
// i have more value's in my array with different 'numbers' in the beginning
so im having trouble with this can anyone help me find a more simple solution which dynamically chop's down the first character's till the '.' ?
You can do something like
var songList = ["1. somesong.mid","13. abcdef.mid","153. acde.mid"];
songList.forEach(function(value, i){
songList[i] = value.replace(/\d+\./, ''); //value.substr(value.indexOf('.') + 1)
});
Demo: Fiddle
You can use the string .match() method to extract the part up to and including the first . as follows:
var newString = myString.match(/[^.]*./)[0];
That assumes that there will be a match. If you need to allow for no match occurring then perhaps:
var newString = (myString.match(/[^.]*./) || [myString])[0];
If you're saying you want to remove the numbers and keep the rest of the string, then a simple .replace() will do it:
var newString = myString.replace(/^[^.]*. */, "");
So, I have to get HTML of textarea and check whether it contains line break. How can i see whether it contain \n because the string return using val() does not contain \n and i am not able to detect it. I tried using .split("\n") but it gave the same result. How can it be done ?
One minute, IDK why when i add \n to textarea as value, it breaks and move to next line.
Line breaks in HTML aren't represented by \n or \r. They can be represented in lots of ways, including the <br> element, or any block element following another (<p></p><p></p>, for instance).
If you're using a textarea, you may find \n or \r (or \r\n) for line breaks, so:
var text = $("#theTextArea").val();
var match = /\r|\n/.exec(text);
if (match) {
// Found one, look at `match` for details, in particular `match.index`
}
Live Example | Source
...but that's just textareas, not HTML elements in general.
var text = $('#total-number').text();
var eachLine = text.split('\n');
alert('Lines found: ' + eachLine.length);
for(var i = 0, l = eachLine.length; i < l; i++) {
alert('Line ' + (i+1) + ': ' + eachLine[i]);
}
You can simply use this
var numberOfLineBreaks = (enteredText.match(/\n/g)||[]).length;
I have this file
var paragraph = "Abandon| give up or over| yield| surrender| leave| cede| let go| deliver| turn over| relinquish| depart from| leave| desert| quit| go away from| desert| forsake| jilt| walk out on | give up| renounce| discontinue| forgo| drop| desist| abstain from|
recklessness| intemperance| wantonness| lack of restraint| unrestraint|
abandoned |left alone| forlorn| forsaken| deserted| neglected| rejected| shunned| cast off | jilted| dropped| ";
with a lot of spacing, so it's giving me that error at the spacings.
then running a loop and alerting the output
var sentences = paragraph.split("|");
var newparagraph = "";
for (i = 0; i < sentences.length; i++) {
var words = sentences[i].split(" ");
if (words.length < 4) {
newparagraph += sentences[i] + "|";
}
}
alert(newparagraph);
how do I read from a file that doesn't get errors from spacing?
As the other answers noted, javascript automatically puts a semicolon at the end of (or what it thinks is) every statement. More about it here.
http://en.wikipedia.org/wiki/JavaScript_syntax#Whitespace_and_semicolons
It doesn't understand text with line-breaks in them. You could use the '\' character to signify your text contains line-breaks.
var text = "this is\
a very long\
sentence";
But the above practice is generally frowned upon. Best bet, define strings in one line or use concatenation (+) to break your strings into multiple lines. If your text must contain line-breaks, use '\n' character.
I can't see a quote character at the end of var paragraph = "... line.
You're missing a terminating quote and semi-colon at the end of the var paragraph assignment. You can use a tool like jslint (http://www.jslint.com/) to check your syntax, if in doubt.