Question

The regular expression I am using is returning too much text. The expression is supposed to strip out a name and date from the text.

var sCurrentText = "(26 JAN 2011) - ILewis Provided excellent translation.";
var sRegxDate    = "\([0-9]{2}[\\\.\/\-, ](Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[\\\.\/\-, ][0-9]{4}\)[, \-]{0,3}[A-z]+ ?\-?\:? ?";
var DatePattern  = new RegExp(sRegxDate, "i");
var sDate        = DatePattern.exec(sCurrentText);
alert(sDate);

I expect:

(26 JAN 2011) - ILewis

But the popup says:

(26 JAN 2011) - ILewis,JAN

Other annoying issues:

1. I am not able to emulate this issue in regexpal. http://regexpal.com/

2.

alert(sDate[0]); 

returns:

(26 JAN 2011) - ILewis

but

oTextbox.value = sDate[0];

results in an empty textbox. Frustrating.

What am I doing wrong?

Answer 1

You are alerting sDate thinking that it is a string, when in fact it is an array. The comma isn’t in the match, it is a separater.

The first element is:

(26 JAN 2011) - ILewis

The second is:

JAN

This is because you have the month bit wrapped in parentheses. It is a capturing group and exec returns capturing groups as part of the result.

You want

sDate[0]

If you are getting an empty textbox from this, there is some other issue here outside of the regex.

You also have some improperly escaped \ in your regex. As it is there, it does not work at all in IE. You need \\ wherever you have a \

EDIT: This fiddle shows the code in action. It works.

http://jsfiddle.net/5azr9/