Study Weekly | Week 1 of April

1. Learning content

1.Overview

P470-P591

• Advanced articles-commonly used categories
• Advanced articles-enumeration class and annotation class
• Advanced articles-JAVA collection
• Advanced articles-generics
• Advanced articles-IO streaming

2.Specific contents

Advanced articles-commonly used categories

Common methods of String

Returns the length of the string, returns the character at an index, determines whether it is an empty string, changes to upper and lower case, removes spaces from the beginning and end, compares whether they are equal, ignores case comparisons, ignores case comparisons, compares content differences, returns characters String (2,7), test whether this string has the specified suffix, whether it contains str2, return the index value of the first occurrence of the specified string, return the index value of the specified string starting after 5, and find the index from the back Value, replace, matchs, split split
String —> basic data type, wrapper class
Call static method of wrapper class parseXxx (str)
basic data type, wrapper class —> String
calls String overloaded valueOf (xxx)

StringBuffer

StringBuilder variable; thread-safe; high efficiency; multithreading does not exist, with StringBuilder; underlayer using char [] storage
StringBuffer variable; thread-safe; low efficiency; underlayer using char [] storage
String immutable ; The bottom layer uses char [] storage to
add, delete, modify, and interpolate length traversal

Date and time

Date

MATH

Advanced articles-enumeration class and annotation class

Enum class Enum

Annotation class

• Future development models are based on annotations. Annotation is a trend framework = annotation + reflection + design mode
• Annotation special tags to call tags through reflection
• @Override…

Advanced articles-JAVA collection

• Structure for storing operations on multiple data objects, referred to as Java container
  

Advanced articles-generics

Advanced articles-IO streaming

3. Problems encountered and reflection

• There are too many knowledge points, and it is easy to be annoying and easy to forget
  .
• Try to ensure learning time and learning efficiency.
  Time goes by, just fight for the day! Study time 3 am 3 pm 2

2. Plan next week

Continue to Advanced P591 ----