Here you can find the source of toString(Iterable
public static String toString(Iterable<String> iterable)
//package com.java2s; /*/*from w w w .ja va2 s .c o m*/ * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ import java.util.List; public class Main { public static String toString(Iterable<String> iterable) { String ret = ""; if (iterable != null) { int count = 0; for (String str : iterable) { if (count == 0) ret = str; else ret += (", " + str); count++; } } return ret; } public static String toString(String[] arr) { String ret = ""; if (arr != null && arr.length > 0) { ret = arr[0]; for (int i = 1; i < arr.length; i++) { ret += (", " + arr[i]); } } return ret; } public static String toString(List<String> arr) { String ret = ""; if (arr != null && arr.size() > 0) { ret = arr.get(0); for (int i = 1; i < arr.size(); i++) { ret += (", " + arr.get(i)); } } return ret; } }