Format the text in JavaScript alert box

Question

How can I format the text in a JavaScript alert box? I need a word in the text to be underlined.

Answer 1

Underline a string using unicode character '\u0332', called a COMBINING LOW LINE

function underline(s) {
    var arr = s.split('');
    s = arr.join('\u0332');
    if (s) s = s + '\u0332';
    return s;
}

var str = underline('hello world'); // "h̲e̲l̲l̲o̲ ̲w̲o̲r̲l̲d̲"

alert(str);

This method is not guaranteed to produce a smooth underline.

Example of confirm() on Firefox 59:

Answer 2

You can use only:

\b = Backspace 
\f = Form feed 
\n = New line 
\r = Carriage return 
\t = tab
\000 = octal character 
\x00 = hexadecimal character 
\u0000 = hexadecimal unicode character

So, you can insert different ASCII characters, but not format them (like italic or bold).

EDIT I also have to mention, that in fact alert acts like toString conversion, so including tags and/or styles is not possible.

Answer 3

Needed this badly, but none of the answers were particular helpful. As two answers suggest the solution is to use unicode, but you have to do this properly! I also wanted a more reuseable solution where I not needed to reinvent the wheel each and every time. So came up with this small javascript function for convenience.

alert('Really need to alert some '+toUnicodeVariant('underlined', 'bold sans', 'underline')+' text');

<script src="https://rawgithub.com/davidkonrad/toUnicodeVariant/master/toUnicodeVariant.js"></script>

Should produce something like this in all major browsers (try run the code snippet above) :

Answer 4

In my case I created internationalization through a JavaScript file. I needed a mnemonic on each button so I was looking for an easy solution. Actually, I've an easy approach to get the wanted result:

\u0332 is the Unicode Character COMBINING LOW LINE

With this character you can underline single letters.

Demonstration:

alert('S\u0332earch - s underlined');

i18n = {};

i18n.SEARCH = "S\u0332earch - s underlined";

document.getElementById('search').innerHTML = i18n.SEARCH;

<button id="search"></button>

Answer 5

You can't. Use external lib as JQuery UI Dialog or your own implementation.

Answer 6

This is not possible. You'd have to use a plugin. If you have jQuery installed there's a bunch to choose from. If not this one looks promising: http://simplemodal.plasm.it/#examples