CODEWITHSUNDEEP
javascriptarraysnode.jsmongoose
Timothy
Timothy

Reputation: 3593

Merging 2 arrays with different value types

Developing in MEAN stack. Express received and process req array parameters (initially string) and Mongoose returns object array property. I am facing very strange problem. Console.log outputs arrays as follows:

var arr1 = [ '5acde7adf7d2520e3b205970', '5acde7c0f7d2520e3b205971' ];
var arr2 = ["5acde7adf7d2520e3b205970","5acde7c0f7d2520e3b205971"];

first array is a JSON.parsed variable, second the property of MangoDB returned array property.

I need to compare arrays and if they different - perform operation.

Lodash isEqual function is always false. Lodash union the same as concat and filter, output arrays as follows (log output): 

[ 5acde7adf7d2520e3b205970,
  5acde7c0f7d2520e3b205971,
  '5acde7adf7d2520e3b205970',
  '5acde7c0f7d2520e3b205971' ]

If I check types of each array value then the first array values are objects the second are strings...

The only way I can property merge arrays is by preprocessing them like: JSON.parse(JSON.stringify(arr1)). Then all values are strings and merged properly as they shall:

[ '5acde7adf7d2520e3b205970', '5acde7c0f7d2520e3b205971' ]

Anybody faced this problem? Probably have some better ideas how to handle it

The best solution I found, for my problem, is to use map function to even array values. Ex:

arr2.map(String)

Upvotes: 0

Views: 125

Answers (1)

CertainPerformance
CertainPerformance

Reputation: 371168

If it's always going to be an array of primitives, it should be quite easy to just compare each of their values like so:

const arr1 = [ '5acde7adf7d2520e3b205970', '5acde7c0f7d2520e3b205971' ];
const arr2 = ["5acde7adf7d2520e3b205970","5acde7c0f7d2520e3b205971"];
const isSame = (arr1, arr2) => {
  if (arr1.length !== arr2.length) return false;
  return arr1.every((arr1elm, i) => arr1elm === arr2[i]);
}
console.log(isSame(arr1, arr2));

The fact that one array may have been defined with double quotes and one with single quotes shouldn't affect anything, since they're already deserialized - it's still an array of strings underneath, not a string itself.

Upvotes: 2

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