replacing a "-" in the numerical text

[Christian Nash]

Hi,

I have a text field in which a user enters a numerical value(+ve or -ve). I want to let him enter the character "-" at the beginning of the number and not in between. How can i achieve this using javascript?

How do i interpret "/^\s*/" and "/\s*$/"?

[Eric Pascarello]

Guessing either of these would work:

  var re = /^\-?\d+$/
  alert("-12".match(re));
  alert("12".match(re));
  alert("1-2".match(re));
 
  var re2 = /^[\-\+]\d+$/
  alert("-12".match(re2));
  alert("+12".match(re2));
  alert("12".match(re2));
  alert("1-2".match(re2));

Eric

[Christian Nash]

Eric/All,
Where can i get more information about stuff like "/^[\-\+]\d+$/" and "/^\-?\d+$/"?

[Bear Bibeault]

Any JavaScript reference worth its salt will include information on its regular expression capabilities.
[ April 19, 2007: Message edited by: Bear Bibeault ]

[Eric Pascarello]

Basic overview: http://www.javascriptkit.com/javatutors/redev.shtml

Eric