Hi, On Wed, 19 Jun 2019 at 14:12, Сергей Цыпанов <sergei.tsypa...@yandex.ru> wrote: > > Hello, > > in JDK code base we have many places (mainly in j.u.Arrays) where we convert > array to String using verbose constructions with StringBuilder. > > As far as we have got StringJoiner for a long time we can use it making the > code more simple.
It may make the code simpler, but it also comes with a hefty performance penalty, taking twice as long in most cases compared to the existing code. A quick benchmark toString'ing int arrays of size 1,10,100,1000 Benchmark (size) Mode Cnt Score Error Units ToString2.toStringExisting 1 avgt 5 16.675 ± 0.327 ns/op ToString2.toStringExisting 10 avgt 5 78.467 ± 1.373 ns/op ToString2.toStringExisting 100 avgt 5 801.956 ± 7.517 ns/op ToString2.toStringExisting 1000 avgt 5 14944.235 ± 155.393 ns/op ToString2.toStringSuggested 1 avgt 5 35.053 ± 0.533 ns/op ToString2.toStringSuggested 10 avgt 5 222.043 ± 10.157 ns/op ToString2.toStringSuggested 100 avgt 5 2150.948 ± 13.285 ns/op ToString2.toStringSuggested 1000 avgt 5 23411.264 ± 201.721 ns/op /Kasper
