JS Practice — Built-in Objects

String.prototype.matchAll() — match index property

📖 Usage Example

const str = 'a1 b2 c3'
const matches = [...str.matchAll(/(w)(d)/g)]
matches.length   // → 3
matches[0][1]    // → 'a'

Use matchAll() with the g flag to iterate over all regex matches and access capture groups in each result.

String.prototype.matchAll() — Match Index

Each match result has an index property indicating where the match starts.

Challenge: Implement matchIndices(str, ch) that returns an array of indices where ch occurs.

matchIndices('abacaba', 'a') // → [0, 2, 4, 6]

💡 Hints (1)