Question

var number = 342345820139586830203845861938475676
var output = []

var sum = 0;
while (number) {
    output.push(number % 10);
    number = Math.floor(number/10);
}

output = output.reverse();


function addTerms () {
    for (i = 0; i < output.length; i=i+2) {
    var term = Math.pow(output[i], output[i+1]);
    sum += term;

}
return sum;
}

document.write(output);
document.write("<br>");
document.write(addTerms());

I am trying to take that large number and split it into its digits. Then, find the sum of the the first digit raised to the power of the 2nd, 3rd digit raiseed to the 4th, 5th raised to the 6th and so on. for some reason, my array is returning weird digits, causing my sum to be off. the correct answer is 2517052. Thanks

Answer 1

You’re running into precision issues within JavaScript. Just evaluate the current value of number before you start doing anything, and the results may surprise you:

>>> var number = 342345820139586830203845861938475676; number;
3.423458201395868e+35

See also: What is JavaScript's highest integer value that a Number can go to without losing precision?

To resolve your issue, I’d store your input number as an array (or maybe even a string), then pull the digits off of that.

This will solve your calculation with the expected result of 2517052:

var number = "342345820139586830203845861938475676";

var sum = 0;
for(var i=0; i<number.length; i=i+2){
  sum += Math.pow(number.charAt(i), number.charAt(i+1));
}

sum;