String[] str = new String[] {"hi","hello"};
StringBuilder[] sbs = new StringBuilder[str.length];
Arrays.setAll(sbs, i -> new StringBuilder(str[i]));String[] str = new String[] {"hi","hello"};
StringBuilder[] sbs=Arrays.stream(str)
.map(s->new StringBuilder(s))
//.collect(Collectors.toList()) // not needed, see comments
// of @RealSkeptic and @Holger
.toArray(StringBuilder[]::new);