JavaScript Regex Problem

Question

Hi all;

Csharp Regex Pattern:

Regex rg = new Regex("(?i)(?<=>)[^<]+(?=</TD>)");

JavaScript Regex Pattern:

var pattern = (?i)(?<=>)[^<]+(?=</TD>);

var result = str.match(pattern);

Csharp Regex pattern work, but javascript regex pattern not work pls help ?

Answer 1

Assuming you have an HTML fragment in form of a string and are in a browser, trying to consume it with JavaScript:

var str = "<TD>33,7</TD><TD>100</TD><TD>20,0</TD>";

var temp = document.createElement("tr");
temp.innerHTML = str;

var tds = temp.getElementsByTagName("td")
for (var i=0; i<tds.length; i++) {
  alert(tds[i].textContent);  // use .innerText in Internet Explorer
}

See? No regular expressions necessary - the browser has a perfectly capable HTML parser built-in, no need to make your own. When using a JavaScript framework like jQuery, the above gets even easier:

$("<TD>33,7</TD><TD>100</TD><TD>20,0</TD>").find("td").each( function() {
  alert( $(this).text() );
});

Answer 2

There aren't lookbehinds, or inline modifiers in JavaScript RE. So we move the (?i) to the end of the regexp: //i. The lookbehind is a bit harder to mimic, so its easier to just accept the fact that it can't be done and instead use a capture group to find what you need:

var pattern = />([^<]+)<\/TD>/i;
var result = str.match(pattern);

// the match you want is in result[1]

EDIT: Seems to work fine on both strings you provided:

"<td class='asd'>sd</td>".match(/>([^<]+)<\/TD>/i)
// [">sd</td>", "sd"]

If you want to match multiple items in the same string you can abuse the replace() method something like this:

var textInTds = []; // empty array we will fill up:
"<td>bla1</td><td class='asd'>sd</td>".replace(/>([^<]+)<\/TD>/ig, function($0, $1) {
  textInTds.push($1); // push onto the array
  return $0; // return the original text so that it doesn't destroy the string
});

// textInTds -> ["bla1", "sd"]