CODEWITHSUNDEEP
javascriptarraysobject
Elijah M
Elijah M

Reputation: 835

How to check for an object of empty arrays

I want to check if an object has only empty arrays left. Here is an example of the object:

var obj = {
   arr1: [0, 1, 2],
   arr2: [1, 2, 3],
   arr3: [2, 3, 4]
};

I have been pop()ing off values from the arrays inside the object and then I need to check if all of the arrays are empty.

One method I have thought of is like so:

var isEmpty = true;
for (var item in obj) {
   if (obj[item] !== 0) {
      isEmpty = false;
   }
}
// now isEmpty reflects the state of all the object's arrays being empty

However, I am wondering if there is a more simple and straightforward solution. I've looked around and answers like this don't work because the object isn't empty, the arrays inside of the object are. My question is kind of the inverse of this one.

Upvotes: 0

Views: 54

Answers (2)

SLePort
SLePort

Reputation: 15461

You can use every method on the object values:

var obj = {
   arr1: [0, 1, 2],
   arr2: [1, 2, 3],
   arr3: [2, 3, 4]
};

const hasEmptyArrays = obj => 
  Object.values(obj).every(arr => arr.length === 0)

console.log(hasEmptyArrays(obj))

Upvotes: 2

Nina Scholz
Nina Scholz

Reputation: 386578

You could get the values and check each array with their length.

const areAllEmpty = object => !Object.values(object).some(({ length }) => length);

console.log(areAllEmpty({ a: [], b: [], c: [] }));   //  true
console.log(areAllEmpty({ a: [1], b: [], c: [] }));  // false
console.log(areAllEmpty({ a: [], b: [1], c: [] }));  // false
console.log(areAllEmpty({ a: [1], b: [2], c: [] })); // false

Upvotes: 2

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