Develop Reference

Issues replacing dashes by <br> with javascript using wordpress

I am trying to replace all dashes(-) by a "br" but it gives me issues.
I have tried
var strNewString = $('.member__designation').html().replace(/-/g,'<br>');
$('.member__designation').html(strNewString);
Here is the html
Before applying the code above
After applying the code above

You likely want
$('.member__designation').each(function() {
this.textContent = this.textContent.replace(/-/g,'<br>')
})
assuming $('.member__designation') only has text and not html
IF there is only SIMPLE HTML like <b> then do
$('.member__designation').each(function() {
this.innerHTML = this.innerHTML.replace(/-/g,'<br>')
})

It looks like you grab all elements with class .member__designation and you replace them with whatever your regex grabs. I think you must change your implementation

How can I replace the content of a div instead append a value using JQuery?

I am pretty new in JQuery and I have the following problem.
I have create this JQuery function that when the user select a file into an input tag having id=rendicontoAllegato it put the name of this file into an hidden div having id=nomeDocumentoRendicontazione into my page
$(document).ready(function() {
$("#rendicontoAllegato").change(function() {
alert("DOCUMENTO dopo selezione: " + $("#nomeDocumentoRendicontazione").text());
var selectedFileName = $("#rendicontoAllegato").val();
$('#nomeDocumentoRendicontazione').append(selectedFileName);
});
});
It works fine but the only problem is that if I first select something asfile1.txt and then select another file as file2.txt into the div having id=nomeDocumentoRendicontazione I will have the concatenation of the 2 files name.
So I will have something like file1.txtfile2.txt and it is not good for me.
How can I replace the value of the div having id=nomeDocumentoRendicontazione instead to append a new value inside it?

You can use the .text() fn if you are dealing with with your data to be inserted as text or .html() fn if you are dealing with html to be replaced
$('#nomeDocumentoRendicontazione').text(selectedFileName);
Or
$('#nomeDocumentoRendicontazione').html(selectedFileName);

Use html() instead of append().
$(document).ready(function() {
$("#rendicontoAllegato").change(function() {
alert("DOCUMENTO dopo selezione: " + $("#nomeDocumentoRendicontazione").text());
var selectedFileName = $("#rendicontoAllegato").val();
$('#nomeDocumentoRendicontazione').html(selectedFileName);
});
});

You have to use
$('#nomeDocumentoRendicontazione').html(selectedFileName);
it will replace the already present HTML of that. OR you can use
$('#nomeDocumentoRendicontazione').text(selectedFileName);
it will do the same but append your data as text.

wrap numbers in span and .not()

This is similar to other questions, but it's about something specific.
The first example doesn't do anything (breaks)
The second example works except that it hacks up html tags (specifically a tags) as well, so href="something with numbers" get hashed and then the whole thing falls apart
Then I get anchors that have their href attributes hashed up with span tags. Obviously that isn't what I want. What am I doing wrong? There must be some way to put all numbers and ", - : ()" inside a span without hashing up the html tags themselves.
$('#main-content p').contents().not("a").html(function(i, v) {
return v.replace( /([0-9(),-:]+)/g , '<span class="number">$1</span>');
});
$('#main-content p').html(function(i, v) {
return v.replace( /([0-9(),-:]+)/g , '<span class="number">$1</span>');
});

You are replacing all number. You need to only select the text nodes within the element. This code is not tested, but should work.
EDIT: You have to also call .contents(). See this answer
EDIT 2: I got it working in this FIDDLE. Let me know what you think. Did you mean to replace special characters as well as numbers?....because that is what is currently happening per your original regEx.
$('p').contents().filter(function () { return this.nodeType === 3; }).each(function(){
$(this).replaceWith($(this).text().replace( /([0-9(),-:]+)/g ,
'<span class="number">$1</span>'));
});

Add actual HTML elements to PRE/CODE contents

I'm trying to create a quick/dirty way to add some syntax highlighting for pre/code tags in html using javascript.
The problem i'm running into, is that if i edit either the text() or html(), I get escaped content. That is, the added tags render as pre/code, or i get a bunch of eascape characters.
Consider the following html:
<pre>
<code class="target">
public interface __iIFoo { }
public class __tBar : __iIFoo { }
var list = new List__/__iIFoo\__();
</code>
</pre>
The goal here is to replace occurrences of __iIFoo with:
<span class="interface">IFoo</span>
So that it can be highlighted with css. And of course, when it's rendered, I don't want to see the actual SPAN tag.
Here's what I've tried:
$(function(){
var iPatt = /__i\w+/g
$.each($(".target").text().match(iPatt), function(i,match){
var replace = '<span class="interface">'+match.substring(3)+'</span>';
$(".target").text(function(){
return $(this).text().replace(match, replace);
});
});
});
This works, BUT, the span tags I'm adding show up in the rendered content e.g. they are just like all the other pre code. I don't want to see it!

Use .html() instead of .text(). When you use .text(), the value is the literal text that you want users to see, so it replaces special HTML characters with entities so they'll show up literally.

DEMO
.text() treats value as text and .html() render it as html content
$(".target").html(function () { //replace text with html
return $(this).text().replace(match, replace);
});

Try using it with html instead:
$(function(){
var iPatt = /__i\w+/g
$.each($(".target").text().match(iPatt), function(i,match){
var replace = '<span class="interface">'+match.substring(3)+'</span>';
$(".target").html(function(){
return $(this).text().replace(match, replace);
});
});
});

As I said in my comment, change the html rather than the text (fiddle).
As a side-note, it's worrisome that you're completely overwriting the contents of .target every time you encounter a match. You should take advantage of RegExp capture groups and perform only one assignment.
(function () {
var iPattern = /__i(\w+)/g,
iTemplate = "<span class='interface'>$1</span>";
$(".target").each(function () {
this.innerHTML = this.innerHTML.replace(iPattern, iTemplate);
});
})();

String manipulation using jQuery

I am wondering how I would remove the vowels from a word on a button click?
Here is what I am trying to do - http://www.marcia.bnmla.com/~marcia/project0.html
I need to use jQuery to remove the vowels in the second box so it displays only consonants when you click the button. I have it where it displays "MRC" as text when the button is clicked and I need to redo it using string manipulation so I can change the word to anything in my code and it will remove the vowels in that word. I am obviously new at this. Please help me!
Here is my code:
<div id="marcia_box">
<p id="marciatext">marcia</p>
<div id="marcia_boxBtn"><button id="marciaBtn">Marcia</button></div>
</div>
$("#marciaBtn").click(function() {
$("#marcia_box").css("background-color","#999");
$("#marciatext").html('mrc');
});

Do you really need jQuery? What about plain old JavaScript?
"abcdef".replace(/[aeiou]/gi, "") // => "bcdf"
How's that?

jQuery allows you to pass a function to .html, which should return a new HTML string. jQuery will pass the old HTML, so you can do something like this:
$("#marciatext").html(function(i, current) {
return current.replace(/[aeiou]/g, "");
});

demo
This one will help you now and in the future for other transformations
specially for toggling between two array keys
var c=0, text=['marcia', 'mrc'];
$("#marciaBtn").click(function() {
$("#marciatext").html( text[ ++c%2 ] );
});

As shown by Jarrett Meyer, removing the vowels has nothing with the jQuery part. But just to show you how to put it together with jQuery (since you said you is really new in it), here is a sample:
$("#marciatext").text($("#marciatext").text().replace(/[aeiou]/gi, ""));