kata-7-solution-get-middle-character.js

// ************************************************************************************
// https://www.codewars.com/kata/56747fd5cb988479af000028/train/javascript
// 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.

// Examples:
// getMiddle("test") should return "es"
// getMiddle("testing") should return "t"
// getMiddle("middle") should return "dd"
// getMiddle("A") should return "A"
// ************************************************************************************


// Solution 1
function getMiddle(string) {
  let middleIndex = string.length / 2;
  if (string.length % 2 == 0) {
    // if the string is even
    return string.slice(middleIndex - 1, middleIndex + 1);
  } else {
    // if the string is odd
    return string.charAt(middleIndex);
  }
}

// Solution 2
function getMiddle(string) {
  let middleIndex = string.length / 2;
  if (string.length % 2) {
    // if its odd you will always get a remainder of 1
    return string.charAt(middleIndex);
  } else {
    // otherwise the string is even
    return string.slice(middleIndex - 1, middleIndex + 1);
  }
}

// Solution 3
function getMiddle(s) {
  let position;
  let length;
  if (s.length % 2) {
    position = s.length / 2;
    length = 1;
  } else {
    position = s.length / 2 - 1;
    length = 2;
  }
  return s.substring(position, position + length);
}

// Solution 4
function getMiddle(s) {
  return s.substr(Math.ceil(s.length / 2 - 1), s.length % 2 === 0 ? 2 : 1);
}