Is there a Javascript/Lodash function to check if an object is missing ANY properties?

LauraDrill
August 15, 2023
317 views
0 votes
2 Answers

I want to check a javascript object to see if any of it’s properties are missing without checking each property individually.

I can use "hasownproperty" or do if/else statements to check if each one is null/undefined, I wanted a shorter way of checking an object.

Answers

Perhaps this?

const hasMissing = obj => {
  const vals = Object.values(obj);
  return vals.filter(val => val !== null && val !== undefined).length !== vals.length
};  
const obj =  { "a":null, "b":"there", "c":0, "d":undefined }
console.log(obj);

console.log(JSON.stringify(obj)); // so we cannot use that

console.log("Missing?",hasMissing(obj))

Use Array::some() on object values (get them with Object.values()) (this will return true if ANY property’s value is null or undefined):

const obj =  { a: null, b: 'there', c: 0, d: undefined };

console.log("Missing?", Object.values(obj).some(v => v === undefined || v === null));

If you want it the fastest possible, write your own function:

const obj =  { a: null, b: 'there', c: 0, d: undefined };

function hasNullProperties(obj){
  for(const k in obj){
    if(obj[k] === undefined || obj[k] === null){
      return true;
    }
  }
  return false;
}

console.log("Missing?", hasNullProperties(obj));

And a benchmark:

<script benchmark data-count="10000000">

const obj =  { a: null, b: 'there', c: 0, d: undefined };

// @benchmark Array::some()

Object.values(obj).some(v => v === undefined || v === null);

// @benchmark custom func
function hasNullProperties(obj){
  for(const k in obj){
    if(obj[k] === undefined || obj[k] === null){
      return true;
    }
  }
  return false;
}

// @run
hasNullProperties(obj);

</script>
<script src="https://cdn.jsdelivr.net/gh/silentmantra/benchmark/loader.js"></script>

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