JavaScript Definitive Guide (sixth Edition)--Chapter 4th

4. Expressions and operators

JavaScript primitive expressions contain constants or direct quantities, keywords, and variables

Initialization expressions for objects and arrays

var matrix = [[1,2,3],[4,5,6],[7,8,9]]; var p = {x:2.4,y:1.2};

function definition expression defines a JavaScript function

var function (x) {return x * x;}

Property-Access Expression

Expression.identifierexpression[expression]

A call expression in JavaScript is a syntax hint that invokes (or executes) a function or method

An object creation expression creates an object and invokes a function called a constructor that initializes the properties of the new object

In operator

The in operator wants its left operand to be a string or can be converted to a string, hoping that its right operand is an object

The expression returns true if the object on the right has a property value named left operand value.

instanceof operator

The instanceof operator expects the left operand to be an object, and the right operand identifies the class of the object

If the object on the left is an instance of the right-hand class, the expression returns true, otherwise false is returned.

JavaScript Definitive Guide (sixth Edition)--Chapter 4th