Help with calculating max, min, and average values from user input

**whiteae** · 09-14-2012 05:55 PM

I'm new to javascript and am trying to make a simple calculator that will get the average, minimum value, and maximum value from a set of user inputs. I have most of it, but it isn't working right and I don't know enough to fix it even though it should be simple. I also don't know what to initialize the min and max values so that if the user inputs a number that it will work right and give the correct max or min number and the intialized value isn't higher/lower than the user input. Thanks in advance.

Code:

	//Prompt user for temperatures
	var userValue;
	var minValue = 32;
	var average;
	var maxValue = 32;
	var numOfInputs = 0;
	var total;
	userValue = prompt("Enter a fahrenheit temperature (i.e. 65). Type 'quit' when you are finished.");
		
	//Loop through results and test data. Do math for correct numbers.
	while(userValue != "quit"){
		userValue = parseFloat(userValue);
		if(isNaN(userValue)){
			alert(userValue + " is not a number.");
		}else if(userValue > 300){
			alert(userValue + " is too large");
		}else if(userValue < -300){
			alert(userValue + " is too small.");
		}else{
			total += userValue;
			numOfInputs++;
			average = total / numOfInputs;
			if(userValue <= minValue){
				minValue = userValue;
			}
			if(userValue >= maxValue){
				maxValue = userValue;
			}
		}		
		userValue = prompt("Enter a temperature (i.e. 65). Type 'quit' when you are finished.");
	}

       //Display output
        document.writeln("You entered " + numOfInputs + " numbers.");
	document.writeln("The Maximum value is " + maxValue);
	document.writeln("The Minimum value is " + minValue);
	document.writeln("The Average value is" + average);

**jalarie** · 09-14-2012 07:35 PM

Initialize your minValue to 301 because you check to make sure all entered values are less than that. Initialize maxValue to -301 similarly.

Force NUMERIC comparisons (default is string) by multiplying by 1 on these lines:

Code:

if(userValue*1 <= minValue*1){
  minValue = userValue;
}
if(userValue*1 >= maxValue*1){
  maxValue = userValue;
}

**whiteae** · 09-14-2012 10:17 PM

Okay thanks. But I think the average part is messing up because its taking in the word quit when the user wants to stop entering numbers. How do I fix that?

You can go here to test it out.
http://einstein.etsu.edu/~whiteae/CS...lab2/index.htm

**Ayşe** · 09-16-2012 06:46 AM

I wrote
var total = 0;
instead of
var total;

Code:

 

<script type="text/javascript">

//Prompt user for temperatures
	var userValue;
	var minValue = 32;
	var average;
	var maxValue = 32;
	var numOfInputs = 0;
	var total=0;
	userValue = prompt("Enter a fahrenheit temperature (i.e. 65). Type 'quit' when you are finished.");
		
	//Loop through results and test data. Do math for correct numbers.
	while(userValue != "quit"){
		userValue = parseFloat(userValue);
		if(isNaN(userValue)){
			alert(userValue + " is not a number.");
		}else if(userValue > 300){
			alert(userValue + " is too large");
		}else if(userValue < -300){
			alert(userValue + " is too small.");
		}else{
			total += userValue;
			numOfInputs++;

			average = total / numOfInputs;
alert("total=  " + total);
alert("averaj=  " + average);
alert(  "numOfInputs = "+ numOfInputs);
			if(userValue <= minValue){
				minValue = userValue;
			}
			if(userValue >= maxValue){
				maxValue = userValue;
			}
		}		
		userValue = prompt("Enter a temperature (i.e. 65). Type 'quit' when you are finished.");
	}

       //Display output
        document.writeln("You entered " + numOfInputs + " numbers.");
	document.writeln("The Maximum value is " + maxValue);
	document.writeln("The Minimum value is " + minValue);
	document.writeln("The Average value is" + average);

</script>

**007Julien** · 09-17-2012 06:16 AM

A simple variant which allow to see (and remove) the entries...

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<meta name="generator" content="PSPad editor, www.pspad.com">
<title></title>
<style type="text/css">
body {font-familly:Garamond;background:#ccc;text-align:center;}
#page {display:block;width:600px;margin:20px auto;padding:20px;background:#fff;}
p {margin:5px 0;}
.nptCls {width:500px;}
</style>
</head>
<body>
	<div id="page">
	<p>Enter temperatures separed by white spaces... </p>  
	<p><input type="text" id="nptTxt" class="nptCls" onkeyup="analyse(event,this)"></p>
	<p id="rsl"></p>	
<script type="text/javascript">
function analyse(e,t){var i,j,k=e.keyCode|| e.charCode,r,s,v;
	if (k!=32) return;
	if (/[^\s\d\.+-]+/.test(t.value)) {alert('Not valid entry !');return}
	v=t.value.replace(/^\s+|\s+$/,'')
	v=v.replace(/\s+/g,' ').split(' ').sort(function(a,b){return a-b});
	s=0;for (j=v.length,i=0;i<j;i++) s+=1*v[i];
	if (!j) return;
	r='Min value : '+v[0]+'<br>Max value : '+v[j-1]+'<br>Average value : '+(s/j).toFixed(2);
	document.getElementById('rsl').innerHTML=r;
}
</script>
</body>
</html>

Thread: Help with calculating max, min, and average values from user input

Thread Tools

Display

Help with calculating max, min, and average values from user input

Average says Nan

Thread Information

Users Browsing this Thread

Bookmarks

Bookmarks

Posting Permissions