i want to do something really simple - to locate numbers for calculation

function...
    var reg_exp = "([0-9\*\/+\-()]*)";

    if( Messege.match( new RegExp(reg_exp) ) ){
        return Messege.replace(new RegExp(reg_exp,'gi'),"[$1]");
    }

...

Using the function above, should do this :

input : "Havelåge 5+5+5-(5*6) sdsd"
output : "Havelåge [5+5+5-(5*6)] sdsd"

but instead it : "[]H[]a[]v[]e[]l[]å[]g[]e[] [5][]+[5][]+[5][]-[]([5][]*[6][])[] []s[]d[]s[]d[]"


what am i doing wrong ???

Try using:

code:

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return Message.replace(/[0-9\*\/+\-()]*/g, "[$1");

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code:

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Message.replace(/([0-9+\-()*\\\/]+)/,"[$1]")

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Well there were parentheses, but they would always return a blank string -- that's why I said it looked flawed...but I didn't try to correct it because (1) not exactly sure what they're trying to accomplish, and (2) since I'm not so good at regular expressions, I figured I'd just leave it as it was..

quote:

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Originally posted by Silentdragon

code:

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Message.replace(/([0-9+\-()*\\\/]+)/,"[$1]")

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Should work

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Actually, ")*" will not look for more ")"s, unless you specify that the ")" in that case is a character, and in that expression ")" is being used to end a sub-match (whatever you call it...).

ohhh... that might explain something... if the ')' is un-escaped, it might make a submatch...

so, i need to escape the ')'

Yes

EDIT: What exactly are you trying to do?

i want to find calculations within a text string...

lets say i write
"hello jim, i have 25*20 dollars"
then my plugin calculated the amount -->
"hello jim, i have 500 dollars"

so i want to match simple math pieces

Well then I think you're going about it wrong. Here is a better way to do it. The code, however, is a bit messy. This will evaluate division, multiplication, addition, and subtraction (/, *, +, -). It uses the eval() function. It accepts decimals and disregards whitespace. However, there is only support for problems with two numbers (3*4*5 won't work).

code:

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var Str = "Did you know that 5 time 5 is 5*5? Did you know that 8 plus 8 is 8+8?";

    var RegExp = /[\d.]+[\s]*[*/+-][\s]*[\d.]+/g;

    Str = Str.replace(RegExp, function(){ var res = eval(RegExp.exec(Str)[0]); RegExp.lastIndex++; return res; } );

---

He had the right solution
Yours doesn't take into account for more numbers (as you said so yourself)

This should work, in red are the changes:

code:

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var reg_exp = /([0-9*/+\-()]+)/gi;
//brackets indicate a set of characters, you don't need to escape anything in here except for the minus sign, which would indicate a range of characters
document.write(Messege.replace(reg_exp,"[$1]"));

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thanks Shondoit - works a bit better

now i need to refine the regexp to capture mathpieces better - currently smileys are also captured because of ')'

so im thinking that a math piece is constructed by:
- a number of brackets '()' zero or more
- at least 2 numbers
- at least one operator '/*-+^'

a math rule is that 2(5+4) == 2*(5+4) so this one needs to be captured aswell

a better choice then looking for mathpieces is to let the user mark a piece himself... with corner brackets '[]' which is many times simpler

Next - how do i EVAL the piece ?? earlier in the thread, a function was written - this is a bit unhandy - and i recall that the function would only process one math piece ?

quote:

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Originally posted by Montago
Next - how do i EVAL the piece ??

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quote:

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Originally posted by Montago
and i recall that the function would only process one math piece ?

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Note that you can't do:

code:

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Str.replace(RegExp,eval("$1"));

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quote:

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Originally posted by deAd
Note that you can't do:

code:

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Str.replace(RegExp,eval("$1"));

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It wasn't in reply, it was just a note
EDIT: Also, I posted an example of using a function in String::replace earlier in this thread...just that my regex was a bit off..

quote:

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Originally posted by deAd
It wasn't in reply, it was just a note
EDIT: Also, I posted an example of using a function in String::replace earlier in this thread...just that my regex was a bit off..

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it worked but you let replace search with a regular expression and when it found a match you searched the string again for that same match, while it already found the match in the first place. In short: your function didn't made much sense logically (aka doesn't teach the proper thing). What you did was like asking a doctor to examine you, and when he lists the problems, you say: screw it, I'll search it myself using that medical reference...

code:

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var s = "Hello there, 1+1 should be 2. And 5-2 will be 3.";
s = s.replace(/([0-9*/+\-()]+)/gi, function($0, $1) { return eval($1) });
Debug.Trace(s);

---

var s = "Hello there, 1+1 should be 2. And 5-2 will be 3.";
s = s.replace(/([0-9*/+\-()]+)/gi, function($0, $1) { return eval($1) });
Debug.Trace(s);

did the trick

now im able to do some more advanced stuff upon those expressions that are found...

also not-find simple chars... when i write a bare number, it is eval'ed so i gotta fix this