திரும்ப அழைப்பதன் மூலம் மாற்றவும்

If a replacement string is not enough, pass a function: str.replace(regex, (match, ...groups) => string). The callback is invoked for every match and its return value becomes the replacement.

'prezzi: 10 20 30'.replace(/\d+/g, (m) => Number(m) * 1.22);
// "prezzi: 12.2 24.4 36.6" (22% VAT)

Callback arguments

str.replace(regex, (match, p1, p2, ..., offset, original, groups) => ...);

• match -- the entire match.
• p1, p2, \u2026 -- the captured groups in order.
• offset -- index of the match in the original string.
• original -- the whole string.
• groups -- object with the named groups (if any).

'2024-03-15'.replace(/(\d{4})-(\d{2})-(\d{2})/, (_, a, m, g) => `${g}/${m}/${a}`);
// "15/03/2024"

The callback gives you arbitrary power: parsing, lookup, conversion, HTML escaping\u2026 everything that a static string cannot do.

Advanced arguments in replace callbacks

The callback function receives several arguments: the full match, each captured group, the offset of the match within the whole text, and the original input string. This enables sophisticated context-based transformation logic.

Try it

Review exercise

Additional challenge