Changing a small amount of text in a textarea to bold

Question

Say I have this text

Lorem ipsum dolor sit amet, consectetur adipiscing elit.

and I want to make the bold

Lorem ipsum dolor sit amet, consectetur adipiscing elit.

If I was to do this in Javascript

function myFunction(obj) {
  var text1 = "Lorem ipsum ";
  var text2 = "dolor sit amet";
  var text3 = ", consectetur adipiscing elit.";
  text2.bold();
  
  obj.value = text1 + text2 + text3;
}

<textArea onmouseup=myFunction(this)>Lorem ipsum dolor sit amet, consectetur adipiscing elit</textArea>

I can't seem to bold the text, any ideas?

Answer 1

As you can't style text inside a textarea,
Here is a solution using a content-editable div instead:
(Inspired by my solution to another question: Change font for selected text using JavaScript)

function changeStyle(style) {
  var sel = window.getSelection(); // Gets selection
  if (sel.rangeCount) {
    // Creates a new element, and insert the selected text with the chosen style
    var e = document.createElement('span');
    e.classList.add(style.value); // Selected style (class)
    e.innerHTML = sel.toString(); // Selected text

    // https://developer.mozilla.org/en-US/docs/Web/API/Selection/getRangeAt
    var range = sel.getRangeAt(0);
    range.deleteContents(); // Deletes selected text…
    range.insertNode(e); // … and inserts the new element at its place
  }
}

.editable {
  width: 360px;
  height: 120px;
  border: 1px solid #ccc
}

.editable .span-0{ /* Added to reset styles correctly */
  font-weight: normal;   /* Reset b */
  text-decoration: none; /* Reset u */
  font-style: normal;    /* Reset i */
}

.editable .span-b{
  font-weight: bold;
}

.editable .span-u{
  text-decoration: underline;
}

.editable .span-i{
  font-style: italic;
}

Highlight text and change style<br>
<select id="select_font" onchange="changeStyle(this);">
  <option value="span-0" selected>None</option>
  <option value="span-b">Bold</option>
  <option value="span-u">Underlined</option>
  <option value="span-i">Italic</option>
</select>
<div contenteditable="true" class="editable">
  Some Content
</div>

(I added other styling options… just because!)

I hope it helps!

Answer 2

The result should be stored like this:

function myFunction(obj) {;
  var text1 = "Lorem ipsum ";
  var text2 = "dolor sit amet"
  var text3 = ", consectetur adipiscing elit.";
  text2 = text2.bold();

  obj.value = text1 + text2 + text3;
}

More info: https://www.w3schools.com/jsref/jsref_bold.asp

Answer 3

As far as I know, we can't style textarea and don't accept any HTML.

text2 = text2.bold()

will return dolor sit amet

but it will appear as text with b-tags.

Answer 4

For divs it would be done like this, however you can not include a span in a textArea, so if the textArea is necessary i cant really help

function myFunction(obj) {;

document.getElementById("span").style.fontWeight="bold";
}

<div onmouseup=myFunction(this) >Lorem ipsum <span id="span">dolor sit amet, </span> consectetur adipiscing elit</div>