随笔分类 - java / 《Java从入口到项目实战》- 李兴华
book
摘要：* replaceAll，replaceFirst ``` String str = "helloworld"; System.out.println(str.replaceAll("l","_"));// 全替换 System.out.println(str.replaceFirst("l","_
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摘要：* contains indexOf, lastIndexOf,startsWith,endWith ``` public class HelloWorld { public static void main(String args[]){// String args[]字符串数组的意思 Strin
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摘要：### demo1 equals equalsIgnoreCase ``` String strA = "mldn"; String strB = "MLDN"; System.out.println(strA.equals(strB)); System.out.println(strA.equal
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摘要：``` public class HelloWorld { public static void main(String args[]){// String args[]字符串数组的意思 String str = "helloworld"; byte data[] = str.getBytes();
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摘要：### demo1 charAt ``` public class HelloWorld { public static void main(String args[]){// String args[]字符串数组的意思 String str = "www.baidu.com"; char c =
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摘要：* String 内容不可修改 ``` public class HelloWorld { public static void main(String[] args){ String str = "www."; str += "mldn."; str += "cn"; System.out.pri
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摘要：``` public class HelloWorld { public static void main(String[] args){ String info = "mldn"; String strA = "www.mldn.cn"; String strB = "www." + info +
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摘要：* 本节课，视频讲的有点抽象。具体内容结合看书来理解看看??????? ### demo ``` public class HelloWorld { public static void main(String[] args){ String strA = "mldn"; String strB =
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摘要：``` public class HelloWorld { public static void main(String[] args){ String input = null; if("yoo".equals(input)){// 如果input “yoo” 颠倒.会报错java.lang.Nu
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摘要：### demo1 ``` public class HelloWorld { public static void main(String[] args){ String strA = "mldn";// 直接赋值定义字符串 String strB = new String("mldn");//构
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摘要：``` public class HelloWorld { public static void main(String[] args){ //String str = "www.mldn.cn";// 直接赋值-String类对象实例化 String str = new String("www.b
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摘要：### demo1 实际项目中经常用到 综合本章很多知识点。 ``` class Member { private String mid ; private String name ; private Role roles [] ; public Member(String mid,String n
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摘要：``` class Member { private String mid; private String name; private Product products[]; public Member(String mid,String name){ this.mid = mid; this.na
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摘要：``` class Dept {// 部门类 private long deptno; private String dname; private String loc; private Emp emps[]; public Dept(long deptno,String dname,String
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摘要：``` class Car { private String name; private double price; private Person person;// 车应该属于一个人 public Car (String name,double price){ this.name = name;
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摘要：``` class Car { private String name; private double price; private Person person;// 车应该属于一个人 public Car (String name,double price){ this.name = name;
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摘要：### demo1 对象数组，静态初始化 ``` class Person { private String name; private int age; public Person(String name,int age){ this.name = name; this.age = age; }
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摘要：``` class ArrayUtil { // 可变参数,传参,不一定非是数组！ public static int sum(int... data){// 可变参数,本质上仍然是数组;变种数组; int sum = 0; for(int temp : data){ sum += temp; }
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摘要：### demo1 java.util.Arrays.sort() 实现排序 ``` class ArrayUtil { public static void printArray(int temp []){ for(int x = 0;x < temp.length;x++){ System.ou
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摘要：* 利用数组角标来置换操作 ``` class ArrayUtil { // 数组转置操作，左右排序颠倒操作; public static void reverse(int data []){ int center = data.length / 2; int head = 0; int tail
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