Array[position] returning NaN when it should be returning a string

November 7, 2021

The Problem:
You are going to be given a word. Your job is to return the middle character of the word. If the word’s length is odd, return the middle character. If the word’s length is even, return the middle 2 characters.

My Solution

function isOdd(num) {
  return num % 2;
}

function getMiddle(str) {
  const middleDigit = (str.length + 1) / 2;
  if (isOdd(middleDigit) === 1) {
    return str[middleDigit];
  } else {
    return str[middleDigit - 0.5] + str[middleDigit + 0.5];
  }
}
console.log(getMiddle(`the`));

But i’m receiving a NaN output, rather than h , where has str[input] deviated from the my intention?

Thanks in advance!

>Solution :

Your execution was a little bit off!

I changed your isOdd function to return a boolean value, instead of a number.
After every calculation of the middle digit I subtracted 1 from the result, as we are working with indexes (and they start the count of the positions at 0, instead of 1).
For the second middle digit when the word length is even, you just have to do "str.length/2", no need for adding or subtracting 1.

    function isOdd(num) {
      return num % 2 === 1;
    }
    
    function getMiddle(str) {
      if (isOdd(str.length)) {
        return str[((str.length + 1) / 2) - 1];
      } else {
        return str[(str.length / 2) - 1] + str[str.length / 2];
      }
    }
    console.log(getMiddle(`the`));
    console.log(getMiddle(`root`));