MDAS calculator

**gits** · Jul 16 '12, 10:26 AM

could you show what you have done already and explain a bit more what changes/requirements you want to have in it?

**lyodmichael** · Jul 16 '12, 10:42 AM

Code:

<script language="javascript">
var av,first,sc;
function displayone()
{
var e;
e=document.forms[0].one.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displaytwo()
{
var e;
e=document.forms[0].two.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displaythree()
{
var e;
e=document.forms[0].three.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displayfour()
{
var e;
e=document.forms[0].four.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displayfive()
{
var e;
e=document.forms[0].five.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displaysix()
{
var e;
e=document.forms[0].six.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}

function displayseven()
{
var e;
e=document.forms[0].seven.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displayeight()
{
var e;
e=document.forms[0].eight.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displaynine()
{
var e;
e=document.forms[0].nine.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function displayzero()
{

e=document.forms[0].zero.value;
document.forms[0].dis.value=document.forms[0].dis.value+e;
}
function add()
{
first=parseInt(document.forms[0].dis.value);
document.forms[0].dis.value=""
av=document.forms[0].plus.value;
return av;
return first;
}
function m()
{
first=parseInt(document.forms[0].dis.value);
document.forms[0].dis.value=""
av=document.forms[0].minus.value;
return av;
return first;
}
function mu()
{
first=parseInt(document.forms[0].dis.value);
document.forms[0].dis.value=""
av=document.forms[0].mult.value;
return av;
return first;
}
function di()
{
first=parseInt(document.forms[0].dis.value);
document.forms[0].dis.value=""
av=document.forms[0].div.value;
return av;
return first;
}
function cal()
{
if(av=="+"){
	sc=parseInt(document.forms[0].dis.value);
	document.forms[0].dis.value=first+sc;
}
if(av=="-"){
	sc=parseInt(document.forms[0].dis.value);
	document.forms[0].dis.value=first-sc;
}
if(av=="*"){
	sc=parseInt(document.forms[0].dis.value);
	document.forms[0].dis.value=first*sc;
}
if(av=="/"){
	sc=parseInt(document.forms[0].dis.value);
	document.forms[0].dis.value=first/sc;
}
}
function ceo()
{
document.forms[0].dis.value="";
}

</script>

this is my reference but i need to compute like this

**gits** · Jul 16 '12, 12:38 PM

as far as i can see from the code you posted, at the moment you have some form-elements that you use to claculate something. note that you cannot return multiple from a function like this:

Code:

function di() {
    first=parseInt(document.forms[0].dis.value);
    document.forms[0].dis.value=""
    av=document.forms[0].div.value;
    return av;
    return first;
}

this function never returns first since it already exits by returning av.

btw. what is really needed? just computing the input like:

Code:

20-8+3*4/2

or even display the steps from the calculation? getting the steps make it much more complex.

**lyodmichael** · Jul 17 '12, 11:49 AM

yes i just need to compute the inpute the number that inputted in the text box.

**gits** · Jul 17 '12, 02:13 PM

then its easy - you might use something like this:

Code:

<html>
<head>
<script type="text/javascript">

function calc() {
    var term   = document.getElementById('term').value;
    var result = eval(term);

    document.getElementById('result').value = result;
}

</script>
</head>
<body>
    <input type="text" id="term"/>
    <input type="button" value="calculate" onclick="calc();"/>
    <br/>
    <input type="text" id="result"/>
</body>
</html>

be aware that this will evaluate everything that you put into the first textfield (you could for example type in alert('foo')), so you probably want some input-validation so that only numbers and operators and may be brackets could be typed in.

**lyodmichael** · Jul 18 '12, 09:33 AM

thanks, but its not follow the MDAS(multiply divide add subtract ) procedure, it's read the first operation you put and then read the followings i wander how to follow the procedure, btw sorry about my english .

**lyodmichael** · Jul 18 '12, 12:18 PM

sir thank i did it, thank for your help thank you so mach . im just a novice in this but i try my best to gadder information.

**gits** · Jul 18 '12, 01:57 PM

thanks, but its not follow the MDAS(multiply divide add subtract ) procedure

it calculates the term mathematicly correct (since it has to - otherwise the language would be completly messed up). i'm not aware what MDAS should mean - from my point of view it just means that multiplication/division is to be calculated before addition/subtraction and may be only those operations are allowed at all. but i might be wrong here - since i don't know that abbreviation (MDAS) and cannot really find something that really defines it - the best explaination i found is mentioned above.

MDAS calculator

MDAS calculator

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