count a specific character in a string

Discussion in 'Javascript' started by Martin Nadoll, Feb 24, 2004.

  1. Hello,

    I am working on a form-validation script.
    There is a input-field where you input a float or integer numper (maximum
    price to output in database-query).

    But my Cold-Fusion Query generates a >error-message, if there is more than
    one dot in that value e.g. 15.60.50

    Is it possible to validate, that there is only one or no dot given as value
    for that field?

    i tried with:
    if (document.myForm.myInputField.value.indexOf(".")>1) {
    alert ("Please not more than one dot!!")
    return false
    }

    but that doesn't work

    Thanks for any help,
    Martin Nadoll
    Martin Nadoll, Feb 24, 2004
    #1
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  2. "Martin Nadoll" <> wrote in message
    news:c1g536$jmc$05$-online.com...
    > Hello,
    >
    > I am working on a form-validation script.
    > There is a input-field where you input a float or integer numper (maximum
    > price to output in database-query).
    >
    > But my Cold-Fusion Query generates a >error-message, if there is more than
    > one dot in that value e.g. 15.60.50
    >
    > Is it possible to validate, that there is only one or no dot given as

    value
    > for that field?
    >
    > i tried with:
    > if (document.myForm.myInputField.value.indexOf(".")>1) {
    > alert ("Please not more than one dot!!")
    > return false
    > }
    >
    > but that doesn't work
    >
    > Thanks for any help,
    > Martin Nadoll
    >
    >


    Probably the most efficient way is looping over the characters and count for
    yourself. You could do a replaceAll with an empty string and compare
    lengths.

    Silvio Bierman
    Silvio Bierman, Feb 24, 2004
    #2
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  3. Martin Nadoll

    Geoff Tucker Guest

    "Martin Nadoll" <> wrote in message
    news:c1g536$jmc$05$-online.com...
    > Hello,
    >
    > I am working on a form-validation script.
    > There is a input-field where you input a float or integer numper

    (maximum
    > price to output in database-query).
    >
    > But my Cold-Fusion Query generates a >error-message, if there is more

    than
    > one dot in that value e.g. 15.60.50
    >
    > Is it possible to validate, that there is only one or no dot given as

    value
    > for that field?
    >
    > i tried with:
    > if (document.myForm.myInputField.value.indexOf(".")>1) {
    > alert ("Please not more than one dot!!")
    > return false
    > }
    >
    > but that doesn't work
    >
    > Thanks for any help,
    > Martin Nadoll
    >


    var yourInput=document.forms['myForm'].elements['myInputField'];

    if (yourInput.value.split(".").length-1 > 1)
    {
    alert ("Please not more than one dot!!");
    return false;
    }

    Works for me
    Geoff
    Geoff Tucker, Feb 24, 2004
    #3
  4. "Geoff Tucker" <> wrote in message
    news:c1ghm3$vmj$...
    >
    > "Martin Nadoll" <> wrote in message
    > news:c1g536$jmc$05$-online.com...
    > > Hello,
    > >
    > > I am working on a form-validation script.
    > > There is a input-field where you input a float or integer numper

    > (maximum
    > > price to output in database-query).
    > >
    > > But my Cold-Fusion Query generates a >error-message, if there is more

    > than
    > > one dot in that value e.g. 15.60.50
    > >
    > > Is it possible to validate, that there is only one or no dot given as

    > value
    > > for that field?
    > >
    > > i tried with:
    > > if (document.myForm.myInputField.value.indexOf(".")>1) {
    > > alert ("Please not more than one dot!!")
    > > return false
    > > }
    > >
    > > but that doesn't work
    > >
    > > Thanks for any help,
    > > Martin Nadoll
    > >

    >
    > var yourInput=document.forms['myForm'].elements['myInputField'];
    >
    > if (yourInput.value.split(".").length-1 > 1)
    > {
    > alert ("Please not more than one dot!!");
    > return false;
    > }
    >
    > Works for me
    > Geoff
    >
    >


    Good idea but I think you should escape the "." because it has special
    meaning in a regexp.

    Silvio Bierman
    Silvio Bierman, Feb 24, 2004
    #4
  5. On Tue, 24 Feb 2004 19:35:51 +0100, Martin Nadoll <> wrote:

    > I am working on a form-validation script.
    > There is a input-field where you input a float or integer numper (maximum
    > price to output in database-query).
    >
    > But my Cold-Fusion Query generates a >error-message, if there is more
    > than one dot in that value e.g. 15.60.50
    >
    > Is it possible to validate, that there is only one or no dot given as
    > value for that field?


    Yes. String validation is best performed with regular expressions. The
    snipped below will check that the number in 'num' is either an integer, or
    a (simple) floating point representation:

    if( /^\d+(\.\d+)?$/.test( num )) {
    // num is valid
    } else {
    // num contains letters, symbols, or more than one dot (.)
    }

    The expression permits the following:

    - A string composed entirely of digits with a minimum of one digit (e.g.
    512)
    - A string that begins with at least one digit, followed by a single dot,
    and ending with at least one digit (e.g. 4.2 or 16.333)

    If users attempt to enter other valid number representations, such as 5e-2
    (0.05), they will fail. Any value that contains a letter or symbol will
    also fail.

    Don't forget: you should always perform validation on the server.
    Client-side validation is no substitute.

    Hope that helps,
    Mike

    --
    Michael Winter
    d (replace ".invalid" with ".uk" to reply)
    Michael Winter, Feb 25, 2004
    #5
  6. Martin Nadoll

    Randy Webb Guest

    Martin Nadoll wrote:
    > Hello,
    >
    > I am working on a form-validation script.
    > There is a input-field where you input a float or integer numper (maximum
    > price to output in database-query).
    >
    > But my Cold-Fusion Query generates a >error-message, if there is more than
    > one dot in that value e.g. 15.60.50
    >
    > Is it possible to validate, that there is only one or no dot given as value
    > for that field?
    >
    > i tried with:
    > if (document.myForm.myInputField.value.indexOf(".")>1) {
    > alert ("Please not more than one dot!!")
    > return false
    > }
    >
    > but that doesn't work


    myVar = document.myForm.myInputField.value.split('.');
    if (myVar.length>2)
    {
    alert('You have entered more than one decimal point');
    }

    --
    Randy
    Chance Favors The Prepared Mind
    comp.lang.javascript FAQ - http://jibbering.com/faq/
    Randy Webb, Feb 25, 2004
    #6
  7. JRS: In article <c1g536$jmc$05$-online.com>, seen in
    news:comp.lang.javascript, Martin Nadoll <> posted at
    Tue, 24 Feb 2004 19:35:51 :-

    >Is it possible to validate, that there is only one or no dot given as value
    >for that field?


    OK = !/\..*\./.test(F.X0.value)

    I've not tested for speed, but a RegExp scan ought to be reasonably
    efficient, and the method generates no additional objects.

    Most validation can be done in a similar manner, with the conditions for
    the test s supplied in an array of object literals - see <URL:http://www
    ..merlyn.demon.co.uk/js-valid.htm>.

    --
    © John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 IE 4 ©
    <URL:http://jibbering.com/faq/> Jim Ley's FAQ for news:comp.lang.javascript
    <URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
    <URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.
    Dr John Stockton, Feb 25, 2004
    #7
  8. Martin Nadoll

    Mick White Guest

    Martin Nadoll wrote:

    > i tried with:
    > if (document.myForm.myInputField.value.indexOf(".")>1) {
    > alert ("Please not more than one dot!!")
    > return false
    > }
    >
    > but that doesn't work
    >
    > Thanks for any help,
    > Martin Nadoll



    return !isNaN(document.myForm.myInputField.value)
    Mick
    Mick White, Feb 25, 2004
    #8
  9. JRS: In article <>, seen in
    news:comp.lang.javascript, Michael Winter <
    d> posted at Wed, 25 Feb 2004 00:04:48 :-
    >
    >Don't forget: you should always perform validation on the server.
    >Client-side validation is no substitute.


    Half true; it applies to cases in which a form is submitted to a server
    for subsequent processing, and acceptance of incorrect entries would be
    against the interests of the page owner. It is a rather common case,
    but it is not the only case. It is perfectly possible to serve a page
    that does processing at the client on client-provided information,
    presenting results to the client; in that case, only client-side
    validation is possible, and if the user suborns the code that's his
    problem.

    --
    © John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 IE 4 ©
    <URL:http://jibbering.com/faq/> Jim Ley's FAQ for news:comp.lang.javascript
    <URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
    <URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.
    Dr John Stockton, Feb 25, 2004
    #9
  10. JRS: In article <>, seen in
    news:comp.lang.javascript, Grant Wagner <>
    posted at Wed, 31 Mar 2004 17:58:31 :
    >
    >Not to mention that the amount of storage and bandwidth required by your
    >posts admonishing people for including "superfluid" information in their
    >attribution has probably far exceeded the amount of storage and bandwidth
    >required by extra information in their attributions.


    Moreover, the "authority" that Lahn quotes is just someone's Web page,
    translated from German.

    The true authoritative documents, the RFCs and the like, clearly
    envisage without disfavour using a full attribution, and discuss how
    different parts of such may be helpful in different circumstances.

    One merit of such would apply in the case of the Lahn rant itself, or
    rather that of the rest of the article. The article which he cites is
    not now present in my newsbase; but, without a dated attribution, I
    cannot see whether it is an aged article, part of a discussion here in
    which there is no longer any interest, or whether the article is in a
    newsgroup that I either do not take or retain for a shorter period.

    Perhaps it has not occurred to Thomas Lahn that one day, when he grows
    up, he may be seeking employment; and an employer, particularly of one
    from a computer-related search, may well try an Internet search. Most
    employers want people who can interact well with others; but not
    monomaniacal despots /in posse/.

    --
    © John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 MIME ©
    Web <URL:http://www.uwasa.fi/~ts/http/tsfaq.html> -> Timo Salmi: Usenet Q&A.
    Web <URL:http://www.merlyn.demon.co.uk/news-use.htm> : about usage of News.
    No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.
    Dr John Stockton, Apr 1, 2004
    #10
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