gistfile1.html

<div><script type="text/javascript"> 
 
	function thoughtful_evaluate(expression) {
		var x = '';
		var chunks = expression.split(/\s/);
		for (i in chunks) {	var chunk = chunks[i];
			if (chunk.match(/^[\+\-\/\*]$/) != null)
				// this chunk is a single operator
				x += chunk;
			else
				x += eval(chunk);
		}
		return eval(x);
	}
 
	function compute_results() {
		var x = document.getElementById('t').value;
 
		if (x.match(/^[1234567890\+\-\/\*\s]*$/) == null) {
			alert('invalid expression; only numbers and arithmetic operators are allowed.');
		}
 
		document.getElementById('standard_result').innerHTML = eval(x);
		document.getElementById('thoughtful_result').innerHTML = thoughtful_evaluate(x);
	}</script>Type an arithmetic expression in the box below and then click "evaluate".     <br /><input value="5+6 * 2" id="t" /><button onclick="compute_results();">evaluate</button>     <br />Below, you see the results of evaluating the above expression under two different schemes: <a href="http://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Operators/Operator_Precedence#Table">JavaScript's standard order of operations</a> and my "thoughtful" order of operations which groups expressions based on whitespace.     <table><tbody>       <tr>         <td><b>standard</b></td>          <td id="standard_result"> </td>       </tr>        <tr>         <td><b>thoughtful</b></td>          <td id="thoughtful_result"> </td>       </tr>     </tbody></table> </div>