keywords, reserved words, identifiers, shortcut keys

Ctrl+y Anti-Revocation

Fast constructor Source (alt+shift+s) Generate Constructor Using Fields ...

Ctrl+alt+↑/↓ copy and paste selected rows

ctrl+shift+/commenting on a selection

Ctrl+shift+\ Dismiss annotations

Alt+↑/↓ move a line quickly

F2 quickly modify the main class name

Alt+shitf+r renaming Refactor-rename

Ctrl+shift+o Quick import of required packages

Ctrl+f Modify all of the same names

Select the loop structure if switch (break jumps out of the switch loop)

IDE Integrated development Tools

Alt+d Quick Check page links

Ctrl+w Close the current page

Alt+f4 Close all Pages

Windows+e Open My Computer.

Windows+d back to the desktop

Identifier

Consists of letters, numbers, underscore "_", dollar Sign "$", the first character cannot be a number.
You cannot use Java keywords and reserved words as identifiers.
Identifiers do not have a length limit.
Identifiers are case sensitive.

Java Keywords
Keywords are pre-defined in the language of a computer, with special identifiers, sometimes called reserved words, and variables of special significance.
Java's keywords have special meanings for Java compilers, they are used to represent a data type, or to represent the structure of a program, and the keyword cannot be used as a variable name, method name, class name, package name, or parameter.
The Java language specifies that the keyword cannot be used as an identifier. There are currently 50 Java keywords, of which the two keywords "const" and "goto" do not have a specific meaning in the Java language. The Java language lists them as keywords, just because "const" and "goto" are keywords for some other computer language.

reserved word (reserved word)
Refers to a word that has already been defined in a high-level language, and the user can no longer use the word as a variable name or procedure name.
Reserved words include keywords and unused reserved words. Keywords are those words that have a specific meaning in the language and become part of the grammar. In some languages, some reserved words may not be applied to the current syntax, which is the difference between a reserved word and a keyword. In general, this may be due to scalability considerations. For example, JavaScript has some future reserved words, such as abstract, double, Goto, and so on.

keywords, reserved words, identifiers, shortcut keys