Java data types, variables, operators, statements.

Data type:
Integral type intlong Short byte
Decimal Doublefloat
Character Char escape character: \ ' (single quote character) \ \ (backslash character) \ n (newline) \ r (carriage return) \ t (horizontal tab, equivalent to tab)
Boolean Boolean

Variable:
Data type variable name [= value] [, variable name [= value]]; ([] The contents can be omitted)
int A;
int b = 1;
int c,d;
int e=2,f=3;

Casting and auto-conversion:--the question to be considered in the process of assigning values.
Conversions between values are implemented using ():
Double A = (int) A
The string becomes an integer, a decimal, a char,boolean:
int a = Integer.parseint ("12");
Float B = float.parsefloat ("3.14");

Operator:
Arithmetic 7+-*/% + +--
Relationship 6> >= < <= = = =!
Logic 3&& | |!
other + = = *=/=%=?: =

Statements: Order

if () {}

Branch

if () {}

else{}

Cycle

if () {}

else if () {}

...

else{}

Java data types, variables, operators, statements.