Develop Reference

Javascript simple word counter

I am trying to make a simple word counter for a textarea element in Javascript. So far I have tried many methods but everyone fails in something. I searched the web but I only found solutions that use functions or JS commands and syntax that I still don't know. The goal is to count the words in a textarea that contains a maximum of 140 characters. The text can also be on more than one line so I have to consider the new line symbol.
Till now I wrote this:
for (let i = 0; i < text.length; i++) {
if (text[i]==' ' && (text[i-1]!==' ' && text[i-1]!=='\n')) {
wc++;
}
else if(text[i]=='\n' && text[i-1]!==' '){
wc++;
}
}
It kind of works but it counts only if after the word I press SPACE. Is there any way to start counting from when the user types just one letter?
EDIT:
I have already tried the .split(" ") method but it doesn't work with the ENTER/RETURN key. My goal is to start counting as soon as the user types a letter.

You can use split along with a regex for whitespace
let words = text.split(/\W/);
wc = words.length;
split breaks your string into an array, it creates a new entry to the array everytime it finds the expression you pass to it.
The regex /\W/ gets whitespaces (' ' and '\n')
So this way it would create an array with every word separated, and then you just need to check the length of the array

Added replace all multiple spaces with single space. Also added check if entered a new line.
document.getElementById("inputField").addEventListener("input", function(e) {
// Get the input text value
var text = this.value;
//replace all multiple spaces with single space
text = text.replace(/\s\s+/g, " ");
// Initialize the word counter
var wc = 0;
// Loop through the text
// and count spaces in it
for (let i = 0; i < text.length; i++) {
if (text[i]==' ' && (text[i-1]!==' ' && text[i-1]!=='\n')) {
wc++;
}
else if(text[i]=='\n' && text[i-1]!==' '){
wc++;
}
}
// Display it as output
document.getElementById("show").innerHTML = wc;
})
<textarea id="inputField" rows=10 cols="60">
</textarea>
<br><br>
<p> Word Count:
<span id="show">0</span>
</p>

Javascript replace already replaced text

I have two textareas written in HTML like this:
<textarea id="checked-words"></textarea>
<br />
<textarea id="words" onkeyup="displayColoredText()"></textarea>
<div id="text-to-insert"></div>
(into the div element, I will insert text, using JavaScript)
My task is to write into the div section the text from the second textarea and make red the occurrences of strings from the first textarea.
Example
If the first textarea contains the following words: aaa, aab and the second contains aaab, all of the characters have to be red. If the second one contains abaa, none of the characters will be red in the div section.
Here is my JavaScript function which displays and colorize the text:
function displayColoredText() {
//Displays the colored text below the second textarea
//Find the two textareas
var firstTextArea = document.getElementById('checked-words');
var secondTextArea = document.getElementById('words');
//Split by spaces
var checkedWords = firstTextArea.value.split(" ");
var text = secondTextArea.value.split(" ");
var textToInsert = secondTextArea.value;
for(i in checkedWords) {
console.log(checkedWords.length);
textToInsert = textToInsert.replace(new RegExp(checkedWords[i], 'g'), '<span class="insertRed">' + checkedWords[i] + '</span>');
}
document.getElementById('text-to-insert').innerHTML = textToInsert;
}
My problem is, that an already replaced text won't be considered, for example, if the first textarea contains aaa and aab and if the second one contains aaab, only the first three characters will be red, instead of the whole string. How can I resolve this?
EDIT: Screenshot of the problem

Your original input from the second text area is pure text, not HTML, so this is the "state" of the data you want to do this in.
This would be my way of implementing it as mentioned in comments, recording which positions have a match first, and then simply looping over all characters in the end to wrap them in a span each:
function displayColoredText() {
//Displays the colored text below the second textarea
//Find the two textareas
var firstTextArea = document.getElementById('checked-words');
var secondTextArea = document.getElementById('words');
//Split by spaces
var checkedWords = firstTextArea.value.split(" ");
var text = secondTextArea.value;
// empty array with keys 0 to length-1 set to undefined
var markedMatches = new Array(secondTextArea.value.length);
for (var i = 0, l = checkedWords.length; i < l; ++i) {
var checkedWord = checkedWords[i],
start = 0,
matchPos;
// check for match from current starting position
while ((matchPos = text.indexOf(checkedWord, start)) !== -1) {
// mark positions from current match start to that plus length of match
for (var k = matchPos, m = matchPos + checkedWord.length; k < m; ++k) {
markedMatches[k] = true;
}
// advance starting position to continue searching
start = matchPos + 1;
}
}
var textToInsert = '';
for (var i = 0, l = text.length; i < l; ++i) {
// wrap in span if markedMatches contains true at this position
textToInsert += (markedMatches[i] ? '<span class="match">' + text[i] + '</span>' : text[i]);
}
document.getElementById('text-to-insert').innerHTML = textToInsert;
}
https://jsfiddle.net/t9xjzkaw/
As I said, you could get more sophisticated in collecting the matches as intervals, or putting multiple adjoining matching characters into a single span element, instead of wrapping each one on its own ... but this does the basic job.

Your problem is how your strings get replaced. Your first string is 'aaa aab'. After replacing for 'aaa' in 'aaab', you get '<span class="insertRed">aaa</span>b'. Trying to find 'aab' in this string will come up with no results. You have to replace from your original string and somehow combine the two. I'm not sure how to do this, but I hope this sets you on the right track.
EDIT:
I think this will work:
Instead of replacing the text in the string, place the beginning coordinate in an array and the end coordinate in a second array. Keep doing this for every word found. Then at all of the beginning coordinates, insert the string '<span class="insertRed">'. At all of the end coordinates, insert the string '<span>'. Here is the JS:
function displayColoredText() {
//Displays the colored text below the second textarea
//arrays with coordinates
var beginnings = [];
var ends = [];
//Find the two textareas
var firstTextArea = document.getElementById('checked-words');
var secondTextArea = document.getElementById('words');
//Split by spaces
var checkedWords = firstTextArea.value.split(" ");
var text = secondTextArea.value.split(" ");
var textToInsert = firstTextArea.value;
for(i in checkedWords) {
console.log(checkedWords.length);
if (firstTextArea.value.indexOf(checkedWords[i]) != -1) {
beginnings.push(firstTextArea.value.indexOf(checkedWords[i]));
ends.push(firstTextArea.value.indexOf(checkedWords[i]) + checkedWords[i].length);
}
}
beginnings.sort(function(a, b){return b-a});
ends.sort(function(a, b){return b-a});
for (b in beginnings) {
textToInsert = textToInsert.slice(0, ends[b]) + "</span>" + textToInsert.slice(ends[b]);
textToInsert = textToInsert.slice(0, beginnings[b]) + '<span class="insertRed">' + textToInsert.slice(beginnings[b]);
}
document.getElementById('text-to-insert').innerHTML = textToInsert;
}
This code is untested, so tell me if something doesn't work and I will change it. Basically, what I am doing is instead of replacing occurrences, I find them first, place them in arrays, and insert the correct text at those coordinates. I hope this helps!

Insert line break every 3 lines in javascript?

Hi I'm still a newbie at javascript so I want to create a script that inserts a line break after every 3 lines. So here's my code I got so far
var num = `http://url.com
http://url2test.com
http://url3nag.com
http://url4lalala.com
http://url5papapapapa.com
http://url6ddadadadad.com
http://url7etet.com
http://url8testtest.com`;
var newNum = num.toString().match(/.{3}/g).join('</br>');
console.log(newNum);
It is doing it wrong. It seems to be inserting every 3characters instead of lines. Can anyone help me fix the code?

You can use the replace function. Try the below code.
var num = `http://url.com
http://url2test.com
http://url3nag.com
http://url4lalala.com
http://url5papapapapa.com
http://url6ddadadadad.com
http://url7etet.com
http://url8testtest.com`;
var newNum = num.replace(/(.*\n.*\n.*\n)/g, '$1<br>');
console.log(newNum);
EDIT
I have made a few changes to the RegEx in the code below. This will allow you to specify the number of lines between which <br> need to be added.
var num = `http://url.com
http://url2test.com
http://url3nag.com
http://url4lalala.com
http://url5papapapapa.com
http://url6ddadadadad.com
http://url7etet.com
http://url8testtest.com`;
var newNum = num.replace(/((.*\n){3})/g, '$1<br>');
console.log(newNum);
In the above RegEx, the .* will match all characters till the end of line and the \n will match the new line character.
(.*\n){3}
I have enclosed this in parenthesis to mark it as a group and used {3} to indicate that the preceding group repeats 3 times.
((.*\n){3})
Then the whole RegEx is enclosed in a parenthesis to use it as the first matched group that can be referenced in the replace section using $1.
You can replace the {3} with any number.

You should avoid using string manipulation when using HTML string. Also using BR to break line is not a good idea as well. You should use a block element instead.
var num = `http://url.com
http://url2test.com
http://url3nag.com
http://url4lalala.com
http://url5papapapapa.com
http://url6ddadadadad.com
http://url7etet.com
http://url8testtest.com`;
var content = document.querySelector('.content');
var urls = num.split('\n');
var temp;
for(var i = 0; i< urls.length; i++) {
if(!temp || (i+1) % 3 === 0) {
if (temp) content.appendChild(temp);
temp = document.createElement('div');
}
var span = document.createElement('span');
span.classList.add('link')
span.innerHTML = urls[i];
temp.appendChild(span);
}
content.appendChild(temp);
.link {
margin: 5px;
}
<div class='content'>
Reference:
Is it sometimes bad to use <BR />?

Split a string of HTML into an array by particular tags

Given this HTML as a string "html", how can I split it into an array where each header <h marks the start of an element?
Begin with this:
<h1>A</h1>
<h2>B</h2>
<p>Foobar</p>
<h3>C</h3>
Result:
["<h1>A</h1>", "<h2>B</h2><p>Foobar</p>", "<h3>C</h3>"]
What I've tried:
I wanted to use Array.split() with a regex, but the result splits each <h into its own element. I need to figure out how to capture from the start of one <h until the next <h. Then include the first one but exclude the second one.
var html = '<h1>A</h1><h2>B</h2><p>Foobar</p><h3>C</h3>';
var foo = html.split(/(<h)/);
Edit: Regex is not a requirement in anyway, it's just the only solution that I thought would work for generally splitting HTML strings in this way.

In your example you can use:
/
<h // Match literal <h
(.) // Match any character and save in a group
> // Match literal <
.*? // Match any character zero or more times, non greedy
<\/h // Match literal </h
\1 // Match what previous grouped in (.)
> // Match literal >
/g
var str = '<h1>A</h1><h2>B</h2><p>Foobar</p><h3>C</h3>'
str.match(/<h(.)>.*?<\/h\1>/g); // ["<h1>A</h1>", "<h2>B</h2>", "<h3>C</h3>"]
But please don't parse HTML with regexp, read RegEx match open tags except XHTML self-contained tags

From the comments to the question, this seems to be the task:
I'm taking dynamic markdown that I'm scraping from GitHub. Then I want to render it to HTML, but wrap every title element in a ReactJS <WayPoint> component.
The following is a completely library-agnostic, DOM-API based solution.
function waypointify(html) {
var div = document.createElement("div"), nodes;
// parse HTML and convert into an array (instead of NodeList)
div.innerHTML = html;
nodes = [].slice.call(div.childNodes);
// add <waypoint> elements and distribute nodes by headings
div.innerHTML = "";
nodes.forEach(function (node) {
if (!div.lastChild || /^h[1-6]$/i.test(node.nodeName)) {
div.appendChild( document.createElement("waypoint") );
}
div.lastChild.appendChild(node);
});
return div.innerHTML;
}
Doing the same in a modern library with less lines of code is absolutely possible, see it as a challenge.
This is what it produces with your sample input:
<waypoint><h1>A</h1></waypoint>
<waypoint><h2>B</h2><p>Foobar</p></waypoint>
<waypoint><h3>C</h3></waypoint>

I'm sure someone could reduce the for loop to put the angle brackets back in but this is how I'd do it.
var html = '<h1>A</h1><h2>B</h2><p>Foobar</p><h3>C</h3>';
//split on ><
var arr = html.split(/></g);
//split removes the >< so we need to determine where to put them back in.
for(var i = 0; i < arr.length; i++){
if(arr[i].substring(0, 1) != '<'){
arr[i] = '<' + arr[i];
}
if(arr[i].slice(-1) != '>'){
arr[i] = arr[i] + '>';
}
}
Additionally, we could actually remove the first and last bracket, do the split and then replace the angle brackets to the whole thing.
var html = '<h1>A</h1><h2>B</h2><p>Foobar</p><h3>C</h3>';
//remove first and last characters
html = html.substring(1, html.length-1);
//do the split on ><
var arr = html.split(/></g);
//add the brackets back in
for(var i = 0; i < arr.length; i++){
arr[i] = '<' + arr[i] + '>';
}
Oh, of course this will fail with elements that have no content.

Hi I used this function to convert html String Dom in array
static getArrayTagsHtmlString(str){
let htmlSplit = str.split(">")
let arrayElements = []
let nodeElement =""
htmlSplit.forEach((element)=>{
if (element.includes("<")) {
nodeElement = element+">"
}else{
nodeElement = element
}
arrayElements.push(nodeElement)
})
return arrayElements
}
Happy code

Guide on word occurrence in a textarea

I have a Textarea box, a textbox and a button. I would like on clicking the button, for the word in the textbox to be checked against words in the textarea and count number of occurrence.
I have tried last 2 days to write a click function to do this but not getting anywhere since not sure what codes or logic follows next. Only managed to read the contents in the textarea but not sure how to get the word in the textbox and search against sentence in textarea.
Please I am a newbie in JQuery so not asking for anyone to write the code but more of a guide if possible. If this question isn't permitted here, I am more than happy to delete it. Thanks

Use string.match() along with processing to ensure the first string is not empty and that there actually is a match. Did the following in jQuery since you seemed interested in using it.
var textVal = $('#textbox').val();
var textArea = $('#textarea').val();
var matching = new RegExp('\\b' + textVal + '\\b','g');
var count = textArea.match(matching);
var result = 0;
if (count !== null) {
result = count.length;
}
http://jsfiddle.net/promiseofcake/t8Lg9/3/

You are looking for string occurrences, so take a look at this thread.
You could do this using match(), as suggested in the comments:
var m = searchText.match(new RegExp(wordMatch.toString().replace(/(?=[.\\+*?[^\]$(){}\|])/g, "\\"), "ig"));
// m.length contains number of matches
But that will also match partial words, like 'fox' in 'foxy'. So another method is to split the input into words and walk over them one by one:
var count = 0;
var words = searchText.split(' ');
for (x in words) {
if (words[x].toLowerCase() == wordMatch) {
count++;
}
}
Take a look at this full example: http://jsfiddle.net/z7vzb/

<input type="text"/>
<textarea>...</textarea>
<button>Get</button>
<div></div>
<script>
$("button").click(function(){
count=$("textarea").text().split($("input[type=text]").val()).length-1;
$("div").html(count);
})
</script>