Here you can find the source of concat(String[] strs)
public static String concat(String[] strs)
//package com.java2s; //License from project: Open Source License import java.util.*; public class Main { public static String concat(String str1, String str2) { return str1.concat(str2); }/*from ww w. j a va 2 s . co m*/ public static String concat(String[] strs) { StringBuilder builder = new StringBuilder(); for (String str : strs) { builder.append(str); } return builder.toString(); } public static String concat(List<String> strs) { StringBuilder builder = new StringBuilder(); for (String str : strs) { builder.append(str); } return builder.toString(); } }