Basic HTML version of Foils prepared 23 June 1997

Foil 36 Numeric Parsing Functions

From JavaScript Tutorial for Certificate Course UC Web applications Certificate -- Summer 97. by Geoffrey C. Fox, Tom Scavo


There are JavaScript functions (not string methods) that convert strings to numbers
parseInt("15") or equivalently parseInt("15",10) both return the number 15 in base 10
The optional second argument is the desired radix so that parseInt("15",8) returns 17 in octal
If input string begins with "0x" the default radix is 16 (hexadecimal) whereas if it begins with "0" the default radix is 8 (octal) Ñ otherwise, the default radix is 10
x = 1 + "1"; // evaluates to "11"
x = 1 + parseInt("1"); // evaluates to 2
parseFloat(string) returns a floating point value
  • var x = "0.0314E+2"; var y = parseFloat(x); // sets y=3.14
On platforms that support it, parseInt and parseFloat return NaN (Not a Number) if parsing fails



Northeast Parallel Architectures Center, Syracuse University, npac@npac.syr.edu

If you have any comments about this server, send e-mail to webmaster@npac.syr.edu.

Page produced by wwwfoil on Wed Apr 1 1998