Empty object in Javascript

Question

I have a weird situation.

I take some values from a form and save it in an object.

I print out the values and it prints fine to the console log. But when I try to access it or print again in next line. It returns empty.

Here is the code.

 var family = {};
    var counter = [];

    counter = document.querySelectorAll(".familyMemberBox input[name='member[]']");

    for(x=0;x<counter.length;x++){
                console.log('for loop');
                family[x] = {};

                member_number = counter[x].value;
                member_type = get_member_type(member_number);
                gender = get_gender(member_number);
                age = get_age(member_number);

                family[x]['type'] = member_type;
                family[x]['Gender'] = gender;
                family[x]['Age'] = age;
    }

    for(x=0;x<counter.length;x++){
        console.log(family[x]);
    }

            console.log('family: '+family[0]);

here is the console output

enter image description here

console.log(family[x]); is logging the object. console.log('family: '+family[0]); is logging the string representation of the object, which is (unless you override it) "[object Object]" — James Thorpe
– James Thorpe, Commented Jun 16, 2015 at 15:48
It's just console formatting. Try: console.log('family: '); console.log(family[0]); — tymeJV
– tymeJV, Commented Jun 16, 2015 at 15:48
That's not an empty object, that's just a string for an object. Try console.log("family", family[0]) instead — Bergi
– Bergi, Commented Jun 16, 2015 at 15:48
Try console.log('family: ', family[0]); instead of console.log('family: '+family[0]); — CD..
– CD.., Commented Jun 16, 2015 at 15:48
This one may explain: stackoverflow.com/questions/14597246/… — saif
– saif, Commented Jun 16, 2015 at 15:55

Josh Beam · Accepted Answer · 2015-06-16 15:48:41Z

1

You're making it a string with this statement: console.log('family: '+family[0]);.

You're implicitly calling .toString() when you concat a string with a plain object. The string version of an object is [object Object]. It's not empty, don't worry.

If you're going to show the string version of an object, you're probably going to want to loop through and print each key and value pair, but that's probably not efficient. If you're dead set on printing family to the console, use a comma:

console.log('family: ', family[0]); // should show two individual statements, not just one coerced string

answered Jun 16, 2015 at 15:48

Josh Beam

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1 Comment

Atif Over a year ago

wow, seems like rookie mistake. Thanks for the detailed answer. I will use it in a loop. This was just to test if I was reading the values fine.

Davin Tryon · Accepted Answer · 2015-06-16 15:48:23Z

1

This line: console.log('family: '+family[0]); is coercing family[0] to a string before printing. It doesn't mean that the object is empty.

Try this instead:

console.log('family: ');
console.log(family[0]);

answered Jun 16, 2015 at 15:48

Davin Tryon

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