CODEWITHSUNDEEP
javascriptmath
Prince Mahmud Hridoy
Prince Mahmud Hridoy

Reputation: 41

java scripts mathematical equation showing wrong answer

I am a new learner of Java Script. I'm having a problem with my mathematical equation. Its showing wrong answer. please help me to find the mistake.

    <html>
    <head>
	<title>calculation of (p+r)*(n+r) </title>

        <script>
            function calculate()
            {
               var p = document.getElementById("p").value;
               var n = document.getElementById("n").value;
               var r = document.getElementById("r").value;
               
			   
               var calculationa= p+r;
			   
			   var calculationb= n+r;
			  
			   
			   var cal_final=Number(calculationa)*Number(calculationb);
			   
			   document.getElementById("result").innerHTML=cal_final;
            }
        </script>
    </head>

    <body>
        <h1>calculation of (p+r)*(n+r)</h1>
        p: <input id="p"><br/>
        n: <input id="n"><br/>
        r: <input id="r"><br/>

       

       <button onclick="calculate()">calculate</button>
	   <p id="result"></p>
    </body>
</html>

It is the equation I want to solve. The math shows this result which is not correct.https://i.sstatic.net/Ir9hs.png

How can i fix this ?

Upvotes: 2

Views: 121

Answers (3)

Banwari Yadav
Banwari Yadav

Reputation: 506

Also can try this .....

function calculate()
            {              

    var p= Number(document.getElementsByName("p")[0].value); 
    var n= Number(document.getElementsByName("n")[0].value);
    var r= Number(document.getElementsByName("r")[0].value);
    var sum1 = p+ r;
    var sum2 = n+ r;
    var res=sum1 *sum2;

    document.getElementsByName("result1")[0].value = res;
                       
            }
 <h1>calculation of (p+r)*(n+r)</h1>
        p: <input type="text"  name="p"><br/>
        n: <input type="text"  name="n"><br/>
        r: <input type="text"  name="r"><br/>
       <br/>
<input type="button" name="add" value ="add" onClick="calculate()" />
result: <input type="text"  name="result1"><br/>

Upvotes: 1

Ankur Bhadania
Ankur Bhadania

Reputation: 4148

In Javascript var value considering as string.

For integer value addition used parseInt().

For Floating value addition used parseFloat().

Please check this for more information http://www.tutorialspoint.com/java/java_numbers.htm

function calculate()
{
   var p = document.getElementById("p").value;
   var n = document.getElementById("n").value;
   var r = document.getElementById("r").value;


   var calculationa= parseInt(p)+parseInt(r);

   var calculationb= parseInt(n)+parseInt(r);


   var cal_final=parseInt(calculationa)*parseInt(calculationb);

   document.getElementById("result").innerHTML=cal_final;
}

Upvotes: 0

Munawir
Munawir

Reputation: 3356

The values are assigned to p, n and r as strings. So, p+r = 1+2 = 12.

Use parseInt() to parse the values as Integer and do calculations. Or use parseFloat()

function calculate() {
  var p = parseInt(document.getElementById("p").value);
  var n = parseInt(document.getElementById("n").value);
  var r = parseInt(document.getElementById("r").value);

  var calculationa= p+r;

  var calculationb= n+r;

  var cal_final=Number(calculationa)*Number(calculationb);

  document.getElementById("result").innerHTML=cal_final;
}
    <h1>calculation of (p+r)*(n+r)</h1>
    p: <input id="p"><br/>
    n: <input id="n"><br/>
    r: <input id="r"><br/>

   <button onclick="calculate()">calculate</button>
   <p id="result"></p>

Upvotes: 2

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