Remove duplicates from array - all data types with shallow objects only.

RemoveDupsFromArr.js

/**
 * @param {{[key: string]: number}} obj1
 * @param {{[key: string]: number}} obj2
 * @return {boolean} equal - Are the two objects equal?
 */
const shallowCompare = (obj1, obj2) => {
  // If passing in undefined values, this means the obj did not exist in the dupsHash in removeDuplicates(), so return.
  if (typeof obj1 !== 'object' || typeof obj2 !== 'object') return;
  
  const obj1Keys = Object.keys(obj1);
  const obj2Keys = Object.keys(obj2);

  if (obj1Keys.length !== obj2Keys.length) return;
  
  let equal = true;
  
  obj1Keys.forEach(key => {
    // If at any point obj1[key] is not defined on obj2[key], return so as to not loop unecessarily.
    if (!equal) return;
    
    obj1[key] === obj2[key] ? equal = true : equal = false;
  })
  
  return equal;
}

/**
 * @param {mixed[]} arr
 * @return {mixed[]} removedDupsArr - An array with all duplicates removed
 */
const removeDuplicates = (arr) => {
    const removedDupsArr = [];
    const dupsHash = {};
    
    for (let i = 0; i < arr.length; i++) {
      const isObj = typeof arr[i] === 'object';
      if (isObj) var objStrKey = JSON.stringify(arr[i]);
      
      if (isObj ? !shallowCompare(arr[i], dupsHash[objStrKey]) : !dupsHash[arr[i]]) {
        isObj ? dupsHash[objStrKey] = arr[i] : dupsHash[arr[i]] = true;
        
        removedDupsArr.push(arr[i]);
      }
    }

    return removedDupsArr;
};

removeDuplicates(
  [[1, 2], [1, 2], [1, 3], {hello: 'world', righteous: 'dude'}, {hello: 'world', righteous: 'dude'}, {hello: 'world'}, 1, 45, 1, 66, 66, 66, 'e', 'e']
);