java - Stream 元素是字符串，用逗号拼接

Question

Stream.of("1","2","3","4")这个是输入
我想得到1,2,3,4的输出，怎么写？

Answer 1

用reduce

Stream.of("1","2","3","4").reduce((a,b) -> a +"," +b))

Answer 2

如果你跟我一樣不懂reduce事幹啥的話

String.join(",", stringStream.collect(Collectors.toList()));

轉變思維有點難啊

Answer 3

雷雷