find-uniq.js

// Find the only element in an array that only occurs once.


// create an object storing the keys as the numbers, and the values as the occurrence
// find the key that has a value of 1, and return that key 
let list = [1,1,2,2,3,3,4,5,5,6,6];

let uniqueNum = (nums) =>{
  let numObj = numCount(nums);
  
  for (var prop in numObj) {
    if (numObj[prop] === 1) {
       console.log(prop);
    }
  }
};


var numCount = (list) => {
  return list.reduce((acc,current) =>{
    var numKey = current.toString();
     acc[numKey] === undefined ? acc[numKey] = 1 : acc[numKey] += 1;
     return acc;
  },{});
};

uniqueNum(list);



// with a double for loop, the number will be the one with a count of 1, indicating it was only compared against itself in the
// double for loop


let doubleForUniq = (list) => {
  let target;
  let count = 0;
  
  list.forEach((num) => {
    target = num;
    count  = 0;
    list.forEach((num2) => {
    	
      if (num === num2) { count += 1 }
    });
    //console.log('-----------------------------');
    if (count === 1) { console.log("found it!!!!",target) }
  });
}

console.log(doubleForUniq(list));