[JAVA] String splicing Efficiency

344. Reverse String

Write a function that takes a string as input and returns the string reversed.

Example:
Given s = "Hello", Return "Olleh".

I wrote a code at the beginning.

class Solution {    public  String reversestring (string s) {        int len = s.length ( );        String ans= "";          for (int i=len-1;i>=0;i--)            ans+ =S.charat (i)        ; return ans;    }}

The last case of the above code did not pass, check the next found that the last cases about more than 42,300 characters

Because I beginner Java, for many details are not very understanding, then looked up some information, and also did some tests, found that compared to StringBuilder

Stitching at 50,000-character levels differs by more than 1600 times in speed. Here is to remind everyone string when using a large number of splicing, as far as possible to replace StringBuilder

[JAVA] String splicing Efficiency