Here you can find the source of startsWith(String str, char prefix)
public static boolean startsWith(String str, char prefix)
//package com.java2s; /**//from ww w .jav a 2 s . com * Copyright 2008-2016 Juho Jeong * * Licensed 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. */ public class Main { public static boolean startsWith(String str, char prefix) { if (str == null || str.isEmpty()) return false; return (str.charAt(0) == prefix); } /** * Returns {@code true} if the given string is null or is the empty string. * * @param str a string reference to check * @return {@code true} if the string is null or is the empty string */ public static boolean isEmpty(String str) { return (str == null || str.length() == 0); } }