`.index` is going to be the fastest because it is directly using NQP ops which are built into the VM.
'abcdefg'.index('de'); # 3 If you want all of the indexes, use `.indices` 'abcdefabc'.indices('abc'); # 0, 6 `.index` will return `Nil` if it doesn't find anything, and `.indices` will return an empty list. 'abc'.index('ZZ'); # Nil 'abc'.indices('ZZ'); # () To see the actual code implementing these (and other similar methods): - .index: https://github.com/rakudo/rakudo/blob/master/src/core/Str.pm6#L255-L284 - .indices: https://github.com/rakudo/rakudo/blob/master/src/core/Str.pm6#L206-L252 - .contains: https://github.com/rakudo/rakudo/blob/master/src/core/Str.pm6#L183-L203 - .rindex: https://github.com/rakudo/rakudo/blob/master/src/core/Str.pm6#L294-L323 On Sat, Feb 2, 2019 at 5:13 AM ToddAndMargo via perl6-users <perl6-users@perl.org> wrote: > > Hi All, > > What is the fastest way to find the index of > a sub string in a string? > > -T