Question

This is clearly a RTFM issue, but after I did so repeatedly I just can’t get the damn thing to work so there are times when asking for help makes sense:

   var text = "KEY:01 VAL:1.10,KEY:02 VAL:2.20,KEY:03 VAL:3.30";
   var pattern = '/KEY:(\S+) VAL:([^,]+)/g';
   //var pattern = '/KEY:(\S+) VAL:(.?+)(?:(?=,KEY:)|$)/g';
   //var pattern = '/KEY:(\S+) VAL:(.+)$/g';
   //pattern.compile(pattern);
   var kv = null;
   var row = 0, col = 0;
   while((kv = pattern.exec(text) != null))
   {
     row = kv[1].charAt(0) - '0';
     col = kv[1].charAt(1) - '0';
     e = document.getElementById('live').rows[row].cells;
     e[col].innerHTML = kv[2].slice(0, kv[2].indexOf(","));
   }

kv[1] is supposed to give “01”
kv[2] is supposed to give “1.10”

…and of course kv[] should list all the values of ‘text’
to fill the table called ‘live’.

But I can’t get to have pattern.exec() succeed in doing that.

Where is the glitch?

Answer 1

First, the delimiters for the RegExp should be /s, there’s no need to put them in ' delimiters. i.e. to get your exec to run properly you should have:

var pattern = /KEY:(\S+) VAL:([^,]+)/g;

Second, you’re assigning a boolean to kv which you don’t want. The while will obviously only evaluate to true if it’s not null so that’s redundant. Instead you just need:

while (kv = pattern.exec(text)) {

That should get your code to work as you desire.