Parse Question

**JMRKER** · 02-28-2007 09:19 PM

In the following script, can someone explain where the extra ',,,,' are comming from, and better yet, how to get rid of them.

For example: 123+456 gives an alert message of ,123,,,,+,,456,,
What I would like to see is: 123,+,456

PHP Code:


<html>

<head>

<title>Parse</title>

<script type="text/javascript">

  function strToTokens(str) {

    str = str.replace(/(\s+)/g,' ');

    var tokens = new Array();

    var tokens_index = 0;

    tokens = str.split(/(\w+)|(\W+)/i);

    alert('StrToTokens:'+tokens);        

  }

</script>  

</head>

<body>

Parse Test<br>

<input type="text" id="StrInfo" value="">

<button onClick="strToTokens(document.getElementById('StrInfo').value)">Action</button>

<input name="tst" type="radio" value="123+456" onClick="document.getElementById('StrInfo').value=this.value">

<input name="tst" type="radio" value="a=12+(-34)+56" onClick="document.getElementById('StrInfo').value=this.value">

<input name="tst" type="radio" value="c2=a^2+b^2" onClick="document.getElementById('StrInfo').value=this.value">

</body>

</html>

The extra radiobuttons are just for testing setup purposes.

Ideally I would like to split a string into Numbers, Variables (letters & numbers) and other characters like *,/,!, etc. to use in an Infix to Postfix (RPN) conversion script.

Any help is appreciated.

**mrhoo** · 02-28-2007 10:34 PM

str.split(/(w+)|(W+)/i);

If you are splitting the input string on either lowercase w's or uppercase W's,
you don't need the i flag. Those are the only two cases w has.

But I don't see where all those ws are coming from.
And why did you replace sequences of the letter s with a space?

str = str.replace(/(s+)/g,' ');

And what is poor tokens_index doing?

**JMRKER** · 02-28-2007 10:59 PM

Thanks for the reply "mrhoo"

If you are splitting the input string on either lowercase w's or uppercase W's,
you don't need the i flag. Those are the only two cases w has.

I'll get rid if the i flag. It was left over from a previous attempt when I was using something like /(\s+)|(\d+)/i and /ig test expressions...

But I don't see where all those ws are coming from.

When I used only the \w or only the \W, I got only numbers and variables with letters. It left out the other characters in the string.

And why did you replace sequences of the letter s with a space?

This was to remove any extra spaces between the "tokens" so they would not show up as blank tokens. In an earlier attempt I had used \s as a split value and was getting incorrect results with extra spaces in the entries.

And what is poor tokens_index doing?

You're right, it is not needed. Again, it was left over from a previous attempt before I tried getting help from this forum.

Thanks for your response ... any other ideas? I'm definitely not an expert on regular expression (regex) formations. It just looked like a good idea at the time.

**JMRKER** · 03-01-2007 11:23 AM

Bump.

Any ideas from the mid-day crowd?
All my late-night lookers seem to have gone to sleep!

**mrhoo** · 03-01-2007 12:14 PM

Try matching:

Code:

function strToTokens(str){
	var tokens= str.match(/(\w+)|(\W+)/g)
	alert('StrToTokens:'+tokens.join(','));
}

strToTokens('124+45-23'); // returns>> '124,+, 45,-, 23'

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