模块课程（2/4）
基本替换和“$1”
In JavaScript, String.prototype.replace(regex, replacement) performs a
pattern match and replaces each match with the given string. With the g
flag it replaces all matches; without it, only the first. replaceAll
forces the global behavior (and requires the g flag on the regex).
'ciao mondo'.replace(/o/g, '0'); // "cia0 m0nd0"
'Mario Rossi'.replace(/(\w+) (\w+)/, '$2 $1'); // "Rossi Mario"References in the replacement string
Inside the replacement string, these are special:
$1,$2, \u2026 -- backreference to the numbered group of the regex.$<name>-- backreference to the named group.$&-- the entire match.- `$`` -- text before the match.
$'-- text after the match.$$-- a single literal$.
const data = '2024-03-15';
data.replace(/(\d{4})-(\d{2})-(\d{2})/, '$3/$2/$1');
// "15/03/2024"Reformat the date by inverting the order. The regex has 3 groups, and in the
replacement string you reference them as $1, $2, $3.
Special references in replacements
Besides $1 and $2, you can use $& to insert the whole matched text, $ for all text preceding the match, and$'` for all text following it. This allows rich replacements even without writing JS code.
Try it
Find every date in the YYYY-MM-DD format with three groups (year, month, day). This way you could use replace to obtain DD/MM/YYYY.
显示提示
Replace \\d+ with \\d{4}, \\d{2}, \\d{2} inside three groups captured with (...).
3 次尝试后可用的解决方案
Review exercise
Find 'first last' as two named groups `nome` and `cognome`, so you could rewrite it as `cognome, nome` using `$<cognome>, $<nome>`.
显示提示
Use (?<nome>\\w+) and (?<cognome>\\w+) separated by \\s+.
3 次尝试后可用的解决方案
Additional challenge
Create a capture pattern to reverse the order of first and last name from `Lastname, Firstname` format to `Firstname Lastname`.
显示提示
Use two capture groups for last and first name; the replacement will be performed via $2 $1.
3 次尝试后可用的解决方案