Counting characters between 2 specified words in a string

Question

This is my text string:

0000> hello world <0000

I want to count the characters between "0000>" and "<0000".

Answer 1

This will work:

s = "0000> hello my name is james, whats yours? <0000";
s.match(/0000>(.*?)<0000/)[1].length // returns 38;

But then again, so will this :-)

s.length - 10; // returns 38

Answer 2

Well, something like this would count everything (including spaces) between 0000> and <0000:

'0000> hello my name is james, whats yours? <0000'
  .split(/0000>|<0000/g)[1].length; //=> 38

Or

'0000> hello my name is james, whats yours? <0000'
     .replace(/0000>|<0000/g,'').length; //=> 38

Answer 3

This will do:

function count(string) {
  var match = /0000>(.*)<0000/g.exec(string);

  if (match.length > 1) {
    return match[1].trim().length;
  } else {
    return null;
  }
}

alert (count("0000> hello my name is james, whats yours? <0000"));

And the jsfiddle demo: http://jsfiddle.net/pSJGk/1/

Answer 4

I'd suggest:

var str = " 0000> hello my name is james, whats yours? <0000",
    start = "0000>",
    end = "<0000",
    between = str.substring(str.indexOf(start) + start.length, str.indexOf(end)).length;

console.log(between);​

JS Fiddle demo.

This doesn't, however, trim the white-space from after the first match, or from before the second. This could be altered, of course, to match any given string delimiters by simply changing the variables.

References:

• indexOf().
• length.
• substring().

Answer 5

function getLengthBetween(str,startStr,stopStr) {
  var startPos = str.indexOf(startStr);
  if(startPos == -1) {
    return 0;
  }
  var startOffset = startPos+startStr.length;
  var stopPos  = str.indexOf(stopStr,startOffset);
  if(stopPos == -1) {
    stopPos = str.length;
  }
  return stopPos-startOffset;
}

Usage:

getLengthBetween("0000> hello my name is james, whats yours? <0000","0000>","<0000");