Can't see output

lynny · 10-16-2012, 04:11 AM

I am creating a program with css, html, and javascript. It needs to convert numbers to roman numerals. I can't seem to get any output. Can anyone give me suggestions?
Thanks!

javascript

Code:

Javascript	
	function convert(d) {
	document.getElementById("output").innerText = value;
		
	if (!+d){
		alert('No data was input');
		return '';
		
	var	digits = String(+d).split("");
		key = ["","C","CC","CCC","CD","D","DC","DCC","DCCC","CM",
		       "","X","XX","XXX","XL","L","LX","LXX","LXXX","XC",
		       "","I","II","III","IV","V","VI","VII","VIII","IX"];
		roman = "";
		i = 3;
	
	while (i--)
		roman = (key[+digits.pop() + (i * 10)] || "") + roman;
		
	return Array(+digits.join("") + 1).join("M") + roman;
	}

html

Code:

....other code above
<body>
	<div id="box">
		<form>
			 <p>
			 	CSE 3420.001<br/> 
			 	Program 3 - Javascript Application<br/>
			 	Don Retzlaff donr@unt.edu
			 </p>
		<input type="text" name="digit" id = "nums" value=""/>
		<!--	<input type="submit" name="button" value="Convert to Roman Numerals" -->
			<button onclick="convert(d)">convert to Roman Numerals</button>
		</form>
		<span id="output"></span>
	</div>
	
</body>
.......other code below

devnull69 · 10-16-2012, 07:18 AM

Several problems

1 - You are handing over the variable "d" to the function convert(). Where do you define "d"? Hint: The value is that of a text field document.getElementById('nums').value and could be extracted inside the function with no parameter at all
2 - You are not outputting anything. The only thing you are doing is returning a value. Returning values from an inline event handler generally doesn't make much sense. You should call a method to output the value(s) to the screen (alert() could be something to begin with). The first line document.getElementById("output").innerText = value; doesn't make any sense because you didn't compute any "value" yet