ग्रुप, कैप्चर और Replace

// Named groups make code clearer
const rx = /(?<y>\\d{4})-(?<m>\\d{2})-(?<d>\\d{2})/;
const hit = rx.exec("Release 2024-01-05");
if (hit) {
  console.log("y:", hit.groups.y, "m:", hit.groups.m, "d:", hit.groups.d);
}

// matchAll with the g flag to get every match and groups
const text = "IDs: A-12, B-7, C-300";
const pattern = /([A-Z])-(\\d+)/g;

for (const match of text.matchAll(pattern)) {
  console.log("letter:", match[1], "num:", match[2]);
}

// Replace order: "2025-09-26" -> "26/09/2025"
const date = "2025-09-26";

// With backreferences
const swapped1 = date.replace(/(\\d{4})-(\\d{2})-(\\d{2})/, "$3/$2/$1");
console.log("swap1:", swapped1);

// With a function for more control
const swapped2 = date.replace(/(?<y>\\d{4})-(?<m>\\d{2})-(?<d>\\d{2})/, function (_all, _y, _m, _d, groups) {
  return groups.d + "/" + groups.m + "/" + groups.y;
});
console.log("swap2:", swapped2);