Given the string representations of two integers, return the string representation of the sum of those integers

Question

For example:

sumStrings('1','2') // => '3'
C# sumStrings("1","2") // => "3"

My code:

function sumStrings(a,b) { 
a = Number(a);
b = Number(b); 
var total = a + b ;
return total.toString();
}

When I try the above code with the following, it has a problem.

sumStrings('712569312664357328695151392', '8100824045303269669937');

I get :

7.125774134884027e+26

Instead of:

712577413488402631964821329

Help please!

Your problem is the number precision. Check out this Q&A: http://stackoverflow.com/questions/1685680/how-to-avoid-scientific-notation-for-large-numbers-in-javascript — Joe Essey, Mar 11 '16 at 16:32

NickT · Accepted Answer · 2016-03-11T16:36:06.460

1

Your result is being returned to you in floating point because it is greater than the maximum integer value.

The max int value in javascript I believe is 9007199254740991.

You can check the limits by viewing: alert([ Number.MAX_VALUE, Number.MIN_VALUE ]);

Edit: If you need big integer math without loss of precision, you need a biginteger library similar to this: https://github.com/peterolson/BigInteger.js

edited Mar 11 '16 at 16:36

answered Mar 11 '16 at 16:31

NickT

This is true but not an answer to the question. – Joe Essey Mar 11 '16 at 16:32
I added an edit, I guess I wasn't clear on the question. If he wants the big numbers, he needs a big Number library to do the math. – NickT Mar 11 '16 at 16:39

1 Answers1