The Odin Project - Fundamentals 4 Exercises - sumAll

Question

I am stuck in the sumAll exercise from the Fundamentals 4 portion of the Odin Project. I managed to pass the test in which I need the result to be ‘ERROR’. However, I cannot figure out the correct code to pass the other tests. Where did I go wrong?

This is the exercise:

const sumAll = require(’./sumAll’)

describe(‘sumAll’, function() {
it(‘sums numbers within the range’, function() {
expect(sumAll(1, 4)).toEqual(10);
});
it(‘works with large numbers’, function() {
expect(sumAll(1, 4000)).toEqual(8002000);
});
it(‘works with larger number first’, function() {
expect(sumAll(123, 1)).toEqual(7626);
});
it(‘returns ERROR with negative numbers’, function() {
expect(sumAll(-10, 4)).toEqual(‘ERROR’);
});
it(‘returns ERROR with non-number parameters’, function() {
expect(sumAll(10, “90”)).toEqual(‘ERROR’);
});
it(‘returns ERROR with non-number parameters’, function() {
expect(sumAll(10, [90, 1])).toEqual(‘ERROR’);
});
});

My code:

const sumAll = function(a, b) {
const arr = [];
if (a < b) {
while (a <= b) {
arr.push(a++);
}
} else if (b < a) {
while (b <= a) {
arr.push(b++);
}
} else {
arr.push(a);
}

if (a < 0 || b < 0) {
return “ERROR”;
} else if (typeof a !== NaN || typeof b !== NaN) {
return “ERROR”;
}
return arr.reduce((a, b) => a + b);
}

module.exports = sumAll

Answer 1

this how it work for me

const sumAll = function (startN, endN) {
//create variable to store total sum
  let sum = 0;

check if input parameter in number:

  if (typeof startN != "number" || typeof endN != "number") return "ERROR";

check if input numbers greter than 0:

  else if (startN < 0 || endN < 0) return "ERROR";

and last check is, if last number greater than the first number then initial number will be the last number otherwise start number will be the initial:

  else if (startN < endN) {
    for (i = startN; i <= endN; i++) {
      sum += i;
    }
  } else {
    for (i = endN; i <= startN; i++) {
      sum += i;
    }
  }

then return sum:

  return sum;
};

you can make all these in one check but this are more readable.

Answer 2

That's how i did it. Quite similar but i avoided using for loops.

const sumAll = function(n,m) {
if (n<0 || m<0 || typeof(m) !== 'number' || typeof(n) !== 'number'){
return 'ERROR'
}else {
if(n<m){
n1 = n
n2 = m 
}else{
    n1 = m
    n2 = n
}
return (n1+n2)*(n2/2)}
};

I first checked whether the input is valid, then decided the values of the two variables depending on which is bigger and finally calculated the sum.