Shulou(Shulou.com)06/02 Report--

This article will explain in detail what the javascript expression is. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

Javascript expressions are: 1, arithmetic expression; 2, string expression; 3, main expression; 4, array and object initializer expression; 5, logical expression; 6, left expression; 7, attribute access expression; 8, object creation expression; 9, function definition expression; 10, calling expression, etc.

This article operating environment: Windows7 system, javascript1.8.5 version, DELL G3 computer

An expression is a unit of code that can be evaluated and resolved to a value. Expressions in JS can be divided into several categories.

Arithmetic expression

String expression

Main expression

Array and object initializer expressions

Logical expression

Left expression

Attribute access expression

Object creation expression

Function definition expression

Invocation expression

Arithmetic expression

Under this category, take all expressions that evaluate to numbers:

1 / 2i++i-= 2i * 2

String expression

Expression that evaluates to a string:

'A'+ 'string'

Main expression

Under this category, variable references, literals, and constants:

20.02'something'truefalsethis / / the current objectundefinedi / / where i is a variable or a constant

There are also some language keywords:

Functionclassfunction* / / the generator functionyield / / the generator pauser/resumeryield* / / delegate to another generator or iteratorasync function* / / async function expressionawait / / async function pause/resume/wait for completion/pattern/i / / regex () / / grouping

Array and object initializer expressions

[] / / array literal {} / / object literal [1,2,3] {a: 1, b: 2} {a: {b: 1}}

Logical expression

Logical expressions use logical operators and resolve to Boolean values:

A & & ba | | bachela

Left expression

New / / create an instance of a constructorsuper / / calls the parent constructor...obj / / expression using the spread operator

Attribute access expression

Object.property / / reference a property (or method) of an objectobject [property] object ['property']

Object creation expression

New object () new a (1) new MyRectangle ('name', 2, {a: 4})

Function definition expression

Function () {} function (a, b) {return a * b} (a, b) = > a * ba = > a * 2 () = > {return 2}

Invocation expression

Syntax for calling a function or method

A.X (2) window.resize () on "what is a javascript expression" this article is shared here, I hope the above content can be of some help to you, so that you can learn more knowledge, if you think the article is good, please share it out for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.