Self-learning notes TBE
Operators are symbols used in arithmetic and mathematics, such as + (plus),-(minus), = (equal), etc.
Shift each bit of the value of interest to the right or left
Operators used when assigning numbers and letters to variables
An operator for dynamically determining the type of an object -Is the object an instance of a class? -Is the object an instance of a child class of a class? · Is the object an instance that implements a particular interface?
⑤ Diamond operator
Added in Java 8 Writing a program in a lambda expression reduces the amount of code and makes it easier to read.
Class modifier (default), public, final, abstract What is inheritance? Extends Type conversion (cast) this and super Interface implements
Variable and method modifiers (default), public, protected, private, final, static
Redefining a method defined in a parent class in a child class Overrides occur in two or more classes that have an inheritance relationship
Defining methods with the same name in the same class The name is the same, but the number of arguments, the type of arguments, and the order are different.
Up to Java SE 6: "generic name" Java SE 7 or later: "Generics"
--"List", "Set" and "Map" are prepared as interfaces. --When actually using it, use a class that implements these interfaces. ・ ArrayList of List is often used ・ List ・ ・ ・ Interface ・ ArrayList ・ ・ ・ ・ It is a class that implements List. -A class that implements the interface of the collection framework like ArrayList is called a collection class.
Package and classpath Classpath Package definition package Use of package import
Exception definition Exception handling try-catch? Finally throw throws
What is a thread? Creating a thread