1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package java.lang; 19 20 21 /** 22 * This interface represents an ordered set of characters and defines the 23 * methods to probe them. 24 * 25 * @since Android 1.0 26 */ 27 public interface CharSequence { 28 29 /** 30 * Returns the number of characters in this sequence. 31 * 32 * @return the number of characters. 33 * @since Android 1.0 34 */ length()35 public int length(); 36 37 /** 38 * Returns the character at the specified index, with the first character 39 * having index zero. 40 * 41 * @param index 42 * the index of the character to return. 43 * @return the requested character. 44 * @throws IndexOutOfBoundsException 45 * if {@code index < 0} or {@code index} is greater than the 46 * length of this sequence. 47 * @since Android 1.0 48 */ charAt(int index)49 public char charAt(int index); 50 51 /** 52 * Returns a {@code CharSequence} from the {@code start} index (inclusive) 53 * to the {@code end} index (exclusive) of this sequence. 54 * 55 * @param start 56 * the start offset of the sub-sequence. It is inclusive, that 57 * is, the index of the first character that is included in the 58 * sub-sequence. 59 * @param end 60 * the end offset of the sub-sequence. It is exclusive, that is, 61 * the index of the first character after those that are included 62 * in the sub-sequence 63 * @return the requested sub-sequence. 64 * @throws IndexOutOfBoundsException 65 * if {@code start < 0}, {@code end < 0}, {@code start > end}, 66 * or if {@code start} or {@code end} are greater than the 67 * length of this sequence. 68 * @since Android 1.0 69 */ subSequence(int start, int end)70 public CharSequence subSequence(int start, int end); 71 72 /** 73 * Returns a string with the same characters in the same order as in this 74 * sequence. 75 * 76 * @return a string based on this sequence. 77 * @since Android 1.0 78 */ toString()79 public String toString(); 80 } 81