How to Check if Arrays in a Object Are All Empty?

This question already has an answer here:

How do I loop through or enumerate a JavaScript object? 29 answers

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So if we want to go through the object and find if every key of that object passes a check, we can use Object.keys and the Array#extra every like so:

var allEmpty = Object.keys(obj).every(function(key){
return obj[key].length === 0
})

This will set allEmpty to a boolean value (true/false), depending on if every time we run the given check obj[key].length === 0 returns true or not.

This object sets allEmpty to true:

var obj = {
    0: [],
    1: [],
    2: []
}

while this sets it to false:

var obj = {
    0: [],
    1: [],
    2: [],
    3: [1]
}

---

An object doesn't have a length property. There are several other ways to loop through an object's values, which you should be able to find.

To check if a value is an array, you can use Array.isArray .

For example:

function objectIsEmpty(obj) {
    return Object.keys(obj).every(function(key) {
      var val = obj[key];  
      
      if (Array.isArray(val) && val.length === 0) {
        return true;
      }
      
      // Other rules go here:
      // ...
      
      return false;
    });
};


console.log(objectIsEmpty({ 0: [], 1: [], 2: [] }));
console.log(objectIsEmpty({ 0: [], 1: [1], 2: [] }));

---

it is not working since your object doesn't have length property.

Try this simple one

function isUnPopulatedObject(obj) { 
    return Object.keys( obj ).filter( function(key){
      return obj[ key ].length > 0;  //if any array has a property then filter will return this key.
    }).length == 0; //used == here since you want to check if all are empty
}

or use every

function isUnPopulatedObject(obj) { 
    return Object.keys( obj ).every( function(key){
      return obj[ key ].length == 0;  
    }); 
}

or use some

function isUnPopulatedObject(obj) { 
    return Object.keys( obj ).some( function(key){
      return obj[ key ].length > 0;  
    }) === false; 
}

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