Platform and version requirements: JS (1.4), Native (1.4)

fun substring(startIndex: Int): String

Returns a new String that contains characters in this string builder at startIndex (inclusive) and up to the length (exclusive).

Exceptions

IndexOutOfBoundsException - if startIndex is less than zero or greater than the length of this string builder.

Platform and version requirements: JS (1.3), Native (1.3)

fun substring(startIndex: Int, endIndex: Int): String

Returns a new String that contains characters in this string builder at startIndex (inclusive) and up to the endIndex (exclusive).

Exceptions

IndexOutOfBoundsException - or IllegalArgumentException when startIndex or endIndex is out of range of this string builder indices or when startIndex > endIndex.