eclipse-run-Data type conversion-environment variable configuration

1. Ability to use Eclipse shortcut keys
CTRL +/single-line comment, click again to cancel;
CTRL + SHIFT +/multiline comment; Ctrl + SHIFT + \ Cancel multiple lines of comment;
CTRL + SHIFT + F formatting code
CTRL + D deletes the cursor in the row
SHIFT + ENTER adds a line below the line of the cursor, regardless of where the cursor is in the line
CTRL + ALT + DOWN ARROW repeat to increment the line code
ALT + SHIFT + x run code
ALT +/auto-complete (Syso will be automatically complete for System.out.println ();)
CTRL + 1 Auto Fix
ALT + SHIFT + A: multi-line editing
ALT + SHIFT + M: Extraction method
ALT + SHIFT + S + C: no parameter construction method
ALT + SHIFT + S + O: Full parameter construction method
ALT + SHIFT + S + H: overriding Equals () and Hashcode () methods
ALT + SHIFT + Z:try-catch shortcut keys
CTRL + O construction method in source code
CTRL + SHIFT + x: Select Letters to capitalize
CTRL + SHIFT + Y: Select letters to lowercase
CTRL + 1 + ENTER: The cursor is placed after the semicolon, and the auto-complete return value

2. Ability to delete and import projects using eclipse
Delete: Check the item--del key
Import: file--import--general-existing Projects into workplace--find the path to your folder

3, can use arithmetic operator to participate in the operation--7 kinds of
+ - * / % ++ --
+ Three usages: numbers added; characters added; string concatenation
a++: First assignment, then self-increment
++a: First self-increment, then assign value

4, can use the assignment operator to participate in the operation--6 kinds of
= += -= *= /= %=

5, can use the comparison operator to participate in the operation--6 kinds
> >= < <= = = =!

6, can use logical operators to participate in the operation--6 kinds of
& | ^ ! && | |

7, can use ternary operator to participate in the operation--1 kinds of
Variable-type variable = expression A! Expression 1: Expression 2;
Expression A is set to take the value of expression 1, otherwise the value of the expression 2;

8, can use the scanner class to obtain the keyboard input data
1) Guide package: Import Java.util.Scanner;
2) New variable: Scanner sc = new Scanner (system.in);
3) receive variable: int c = Sc.nextint ();

9. Ability to understand two types of data conversion
1) Implicit conversions: The same type, the converted type is larger than the pre-conversion type, and any data type and string operation are converted to string type
2) Cast: Byte a = (byte) 300;

10. Environment variable Configuration

• Create a new variable name: Java_home
• Computer-Right-click Properties-Advanced system Settings-advanced-environment variables-system variables
• Add variable values for Java_home: JDK installation directory
• At the front of the PATH environment variable, add the following:%java_home%\bin;

eclipse-run-Data type conversion-environment variable configuration