Lexical Structure of a JavaScript Program

Lexical Structure of a JavaScript Program

The lexical structure of a programming language is the set of elementary rules that specifies how to write programs in that language. It is the lowest-level syntax of a language. The Lexical structure specifies variable names, the delimiter characters for comments, and how one program statement is separated from the next.

•         Though JavaScript is a case-sensitive language. It is good programming practice to type the command in lowercase.

•        JavaScript ignores spaces that appear between tokens (identifiers, operators, punctuator, constants and keywords) in programs.

•        JavaScript supports two styles of comments. Any text follow a “//” and the end of a line is treated as a single line comment and is ignored by JavaScript. Any text between the characters “ /* */” is also treated as a multiline comment.

•         JavaScript uses the semicolon (;) to separate statements. Many JavaScript programmers use semicolons to explicitly mark the ends of statements.

•         A literal is a data value for variable that appears directly in a program.

•         An identifier is simply a name. In JavaScript, identifiers are used to name variables, functions and to provide labels for certain loops in JavaScript code.

•         In JavaScript certain keywords are used as reserved words, These words cannot used as identifiers in the programs