This method does not return until the entirearray is populated, and therefore it can introduce latency at the beginning of the operation.
这个方法等到填入整个阵列之后才会传回,因此会在作业开头时引入延迟。
3
This is the most flexible way to concatenate strings because you can use it to append just one string, a few strings at a time, or an entirearray of strings.