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This article mainly explains "what are the javascript lexical keywords". The explanation in the article is simple and clear and easy to learn and understand. Please follow the editor's train of thought to study and learn "what are the javascript lexical keywords"?

Javascript is an interpretive language.

In fact, languages are interlinked. To some extent, computer languages are similar to Chinese, English and other languages. In fact, the initial stage of learning a language is to write strokes, words, grammar, and rules of speaking. The completion of a program is equivalent to writing an article in this language, long or short, or recording history, or describing phenomena, or making calculations, or making induction, statistics, and so on.

So what is the basis or essence of computer language, that is, the change of electronic signals, or 1pc0. It is then used to calculate as if the human brain is thinking with words that it is familiar with. A variety of high-level languages have been created on the basis of 1B0. the high-level language is based on English and allows people to communicate with the computer in a way similar to human language and let the computer respond. Javascript is one of them, and the advantages of this language are reflected in Web front-end development.

Language is made up of words, so the way words are formed is called morphology, and words can also be called identifiers in computer language.

The morphology of javascript:

Character set

1. All the encoded words are composed of characters. The character set of javascript uses the unicode character set. Unicode is the superset of asscii code table and lantin-1. It basically supports all languages in use on earth.

2. Case-sensitive. Javascript is a case-sensitive language. An and an are two different words.

3, the space between the two identifiers will be ignored, in most cases, newline characters will be ignored, pay attention to the coding format, a good coding format is helpful to read. Format control character: affects text formatting but does not display the symbol.

4. Unicode escape sequence, using 6 asscii codes, starting with\ u, followed by 4-digit hexadecimal numbers, referring to any unicode internal code. Such as'\ u0075\ u006e\ u0069\ u0063\ u006f\ u0064\ u0065.

5, standardization, unicode coding, it is possible to use different encoding methods to the same characters, but the internal 1Magin0 encoding is different. Unicode gives a standard encoding (interpretation) for all characters by default.

Comments: two formats of comments, single-line comments / / multi-line comments / * multi-line * /.

Identifiers: you can start with an underscore, $, a letter, not a number. Identifiers are used to name variables and function names.

Variable: there is an identifier to represent the variable name, and the value of the variable can be changed.

Direct quantity: 1 / / integer, 1 / 1 / decimal, 'hello' / / string, true false// Boolean value, / js / / regular expression (used for pattern matching), {} / / object, [] / / array, null / / null value.

Method of defining variables: var sin30='0.5'

Var pai=3.1415926

Var bool=true

Optional semicolon: javascript thinks it is a complete sentence, if there is no semicolon, it will fill in the semicolon, write the semicolon, and form a good coding habit.

Keywords reserved words: javascript uses keywords that users can no longer customize identifiers, and some reserved keywords that may not be used in the current version, for backup.

Here are all the keywords for ECMAScript:

Break case catch continue default delete do else finally for function if in

Instanceof new return switch this throw try typeof var void while with

There are also some reserved words:

Abstract boolean byte char class const debugger double enum

Export extends final float goto implements

Import int interface long native package private protected public

Short static super synchronized throws transient volatile

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