Objects and functions are the other fundamental elements in the language. You can think of objects as named containers for values, and functions as procedures that your application can perform.
Data type conversion
var answer = 42
And later, you could assign the same variable a string value, for example,
answer = "Thanks for all the fish..."
x = "The answer is " + 42
y = 42 + " is the answer."
The first statement returns the string "The answer is 42." The second statement returns the string "42 is the answer."
For more information on these functions, see Chapter ,
"Built-in objects and
For more information on using
frames and windows,
see Chapter 3, "Using
You can access global variables declared in one window or frame from another window or frame by specifying the window or frame name. For example, if a variable called phoneNumber is declared in a FRAMESET document, you can refer to this variable from a child frame as
Integers can be expressed in decimal (base 10), hexadecimal (base 16), and octal (base 8). A decimal integer literal consists of a sequence of digits without a leading 0 (zero). A leading 0 (zero) on an integer literal indicates it is in octal; a leading 0x (or 0X) indicates hexadecimal. Hexadecimal integers can include digits (0-9) and the letters a-f and A-F. Octal integers can include only the digits 0-7.
Some examples of integer literals are: 42 0xFFF, and -345.
A floating-point literal can have the following parts: a decimal integer, a decimal point ("."), a fraction (another decimal number), an exponent, and a type suffix. The exponent part is an "e" or "E" followed by an integer, which can be signed (preceded by "+" or "-"). A floating-point literal must have at least one digit, plus either a decimal point or "e" (or "E").
Some examples of floating-point literals are 3.1415, -3.1E12, .1e12, and 2E-12
The Boolean type has two literal values: true and false.
A string literal is zero or more characters enclosed in double (") or single (
') quotation marks. A string must be delimited by quotation marks of the same type; that is, either both single quotation marks or double quotation marks. The following are examples of string literals:
For characters not listed in Table 5.1, a preceding backslash is ignored, with the exception of a quotation mark and the backslash character itself.
You can insert quotation marks inside strings by preceding them with a backslash. This is known as escaping the quotation marks. For example,
var quote = "He read "The Cremation of Sam McGee" by R.W. Service."
The result of this would be
He read "The Cremation of Sam McGee" by R.W. Service.
To include a literal backslash inside a string, you must escape the backslash character. For example, to assign the file path
c:temp to a string, use the following:
var home =