AJAX - The Complete Reference

PART IV

Appendix A: JavaScript Quick Reference 563

NNOTEOT E While encodeURIComponent() and escape() are commonly deemed useful for preparing

data for Ajax-based transmission, neither works properly for true x-www-urlencoded

formatting. See Chapter 4 for more details on the absolute method for correct encoding.

Array Literals

JavaScript supports arrays both in an object and literal style. Array literals are used with the

following syntax (the brackets are “real” brackets and do not indicate optional components):

[element1, element2, ... elementN]

Each elementN is optional, so you can use an array with “holes” in it, for example:

var myArray = ["some data", , 3.14, true ];

Property Description

decodeURI(encodedURI) URI-decodes the string encodedURI and returns the

result

decodeURIComponent(uriComponent) URI-decodes the encodeURIComponent-encoded

string uriComponent and returns the result

encodeURI(string) URI-encodes the string string and returns the result

encodeURIComponent(string) URI-encodes the string string and returns the result

escape(string) URL-encodes string and returns the result

eval(x) Executes the string x as if it were JavaScript source code

Infinity The special numeric value Infinity

isFinite(x) Returns a Boolean indicating whether x is finite (or

results in a finite value when converted to a number)

isNaN(x) Returns a Boolean indicating whether x is NaN (or

results in NaN when converted to a number)

NaN The special numeric value NaN

parseInt(string [, base]) Parses string as a base-base number (10 is the default

unless string begins with “0x”) and returns the primitive

number result (or NaN if it fails)

parseFloat(string) Parses string as a floating point number and returns the

primitive number result (or NaN if it fails)

undefined Value corresponding to the primitive undefined value

(this value is provided through Global because there is

no undefined keyword)

unescape(string) URL-decodes string and returns the result

TABLE A-9 Properties of the Global Object