How can I create a heading without reformatting the rest of the text?

I am trying to create a table of contents. I have highlighted the heading that I want to format to be the heading for the table of contents, but when I try to add the heading style it changes all of the text on the page, not just the heading I selected. I can’t find a workaround for this and it appears to be bad program design. Can someone help me fix this please? Why can’t I just highlight my selection and change only that?

Is your text divided to paragraphs (using “Enter”), or does it use line breaks (using “Shift+Enter”)? In the latter case, your text is actually a single paragraph, and that’s bad document design.

Do you “add the heading style” by double-clicking an existing style name on Styles pane (F11), or do you edit current paragraph style e.g. right-clicking the text and choosing Paragraph->Edit Style? In the latter case, you are likely modifying a style used by all the text, and that is a user error.

Please describe your problem fully, and try to avoid assertions that are irrelevant at the moment (e.g., only after you know what the issue actually is, can you derive conclusions about bad design).

By the way, there’s also a way to make only some part of a paragraph to be a “heading” - but then it should be done using Insert->Table of Contents and Index->Index entry.

I’ve already described the error, what more do you need. I should be able to highlight the text and apply the desired effect. It’s not bad document design at all, it’s just this faulty feature.

If you apply paragraph style to something that is not a paragraph, it’s a user error not understanding what paragraph is, and what paragraph style is. Working as intended is not a faulty feature; persisting in own ignorance is.

@Random11, maybe this can give you some understanding here.