matchAt

Attempts to match a regular expression exactly at the specified index in the input char sequence.

Unlike matchEntire function, it doesn't require the match to span to the end of input.

fun main(args: Array<String>) {
//sampleStart
val releaseText = "Kotlin 1.5.30 is released!"
val versionRegex = "\\d[.]\\d[.]\\d+".toRegex()
println(versionRegex.matchAt(releaseText, 0)) // null
println(versionRegex.matchAt(releaseText, 7)?.value) // 1.5.30
//sampleEnd
}

Exceptions

IndexOutOfBoundsException - if index is less than zero or greater than the length of the input char sequence.

Return An instance of MatchResult if the input matches this Regex at the specified index or null otherwise.