在段落换行到下一行之前如何获取字符数？

Question

I'm trying to count how many characters are displayed in the first line of a text which is wrapped because the width of the span is limited.

I know that counting the characters of a String can be done with "length", but I'm failing to get the first line.

Example:

 #divone { width: 80px; overflow: hidden; } 

 <div id="divone"> <p id="one">Some long text <p> </div> 

Displayed the text appears as first line: "some long" and second line "text"

Expected output from JavaScript:

Some long

Pseudocode I thought to solve it:

1. Detect which is the last word before the text is wrapped

2. Look this word up in original text and retrieve a substring

3. Use length() to count characters of the substring.

Answer 1

Thanks to comments I found I solution which is approx. what I want:

How to count number of characters in a line using JavaScript