Java Basics Summary

1.8 Basic data types

Integral type: byte short int long

Float type: float double

Character type: Char

Boolean type: True,false

Java type, + on both sides of the default is an int type cast example: int a = four byte num = (byte) a

2. Reference data type: String class

3. Naming conventions

A. Class names cannot start with numbers, special symbols, lowercase letters

b, using small hump-type naming

c, do see the name of the idea

Package naming: All lowercase company names. Name of the project.

4. Array 1. Array type identifier [] = new data type {value 1, value 2}

2. Array type identifier []= {value 1, value 2}

5. Functions

Format: Permission modifier return value type function name (type parameter) {}

Example public String Demo () {

}

6. Object-oriented

Features: Encapsulation inheritance polymorphism

Create object class Name Object name = new class name ();

Invocation of the method

static invocation of static class name calls static invoke non-static instantiation call

1. Anonymous objects

Definition: An object without a name

Features: 1. No meaning when assigning a value to a property

2. Used when calling the method, and can only use 1 times

3. Can be used as a parameter pass

2. Blood Loss model-encapsulation

Definition: Hides the properties and implementation details of an object, providing only public access.

Function: Hide detail security to improve code reuse

Principle: Hide content that does not need to be provided externally and provide interfaces using getter and setter methods.

This keyword: a reference to the current object to distinguish between local variables and global variables with duplicate names

Overloading (overload): In the same class, the method name is identical, and the parameter list [parameter type Order] is different, regardless of the return value.

　　　　

Summary of Java Basics