In Vue.js, if you simply add multiple whitespaces in a string, it eventually displays a single whitespace.

//This will display a single whitespace.
'ab   c'

If you want to display multiple whitespaces, you could use unicode to represent whitespace.

let str1 = 'ab\u00A0\u00A0\u00A0 c';
let str2 = 'ab\u0020\u0020\u0020 c';
let str3 = 'ab\u3000\u3000\u3000 c';

These will output multiple whitespaces in strings.