Java版本:1.8开始 import java.time.LocalDate; import java.time.LocalDateTime; /** * Created by Frank */ public class DateParse { public static void main(String[] args) { String armisticeDate = "1914-11-11"; LocalDate alD = LocalDate.parse(armisticeDa…

今天给大家分享一个Java经典的面试题,题目是这样的: 本题是LeetCode题库中的49题. 将一个字符串数组进行分组输出,每组中的字符串都由相同的字符组成 举个例子:输入["eat","tea","tan","ate","nat","bat"] 输出[["ate","eat","tea"],["nat",…

使用for循环和String对象的charAt()方法:或者,使用"for each"循环和String对象的toCharArray()方法. /** * Created by Frank */ public class StrCharAt { public static void main(String[] args) { String a = "A quick bronze fox lept a lazy bovine"; for (int i = 0; i &…

使用StringBuilder类的reverse()方法来实现. /** * Created by Frank */ public class StringRevChar { public static void main(String[] args) { String sh = "ABCDEFG"; System.out.println(sh + "->" + new StringBuilder(sh).reverse()); } }…

import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Created by Frank * 替换匹配的文本 */ public class ReplaceDemo { public static void main(String[] args) { // 创建一个正则表达式模式,用以匹配一个单词(\b=单词边界) String patt = "\\bfavor\\b"; // 用于测试的输入字符串 S…

import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Created by Frank */ public class REMatch { public static void main(String[] args) { String patt = "Q[^u]\\d+\\."; Pattern r = Pattern.compile(patt); String line = "Order…

import java.util.regex.Pattern; /** * Created by Frank * 在Java中使用正则表达式:测试模式 */ public class RESimple { public static void main(String[] args) { String pattern = "^Q[^u]\\d+\\."; String[] input = {"QA777. is the next flight. It is on time.&q…

需求:  计算一个字符串中每个字符出现的次数 思路: 通过toCharArray()拿到一个字符数组--> 遍历数组,将数组元素作为key,数值1作为value存入map容器--> 如果key重复,通过getKey()拿到value,计算value+1后存入 代码如下: import java.util.*; public class MapDemo { public static void main(String[] args) { String str = "sdnasjhdas…

编写自己的Iterator,实现Iterator接口,这里多说一句,实现Iterable后,可以用"foreach"循环遍历你的对象. import java.util.Iterator; import java.util.NoSuchElementException; /** * 演示Iterator和Iterable接口,并说明怎样编写一个用于对象数组的简单迭代器. */ public class AarrayIterator<T> implements Iterabl…

Java版本:1.8开始 import java.time.Instant; import java.time.ZoneId; import java.time.ZonedDateTime; /** * Created by Frank */ public class CurrentDatetime { public static void main(String[] args) { // 纪元秒和本地日期时间互换 Instant epochSec = Instant.ofEpochSecond…