Upsizes the string to a length of n characters (utf code units).
If n is smaller or equal than the current string length, the current value doesn't change.
If n is greater than the current string length, the current content is extended by inserting at the end as many characters as needed to reach a size of n.
If ch is specified, the new elements are initialized as copies of ch, otherwise, they are _.
Upsizes the string to a length of n characters (utf code units).
If n is smaller or equal than the current string length, the current value doesn't change.
If n is greater than the current string length, the current content is extended by inserting at the end as many characters as needed to reach a size of n.
If ch is specified, the new elements are initialized as copies of ch, otherwise, they are _.