Check if an object has empty properties [duplicate]

Question

Let's say I have the following JS Object

data = {
    name: "John",
    dataOfBirth: "",
    externalId: 2548,
    email: "[email protected]",
    mobile: ""
}

I will receive an object like this with many more properties that can be either String, Integer or undefined. For me to update my database, I cannot override a valid information with an empty one.

I could try if (data.email === "") delete data.email with all of them, but that seems unpractical to maintain.

Is there any way I can scan all properties without having to name every single one of them and remove all empty/undefined ones?

Answer 1

You could simply loop through the object keys and check for each element if they value is blank.

var data = {
        name: "John",
        dataOfBirth: "",
        externalId: 2548,
        email: "[email protected]",
        mobile: ""
    }

    for(var key in data) {
        if(data[key] === "") {
           console.log(key + " is blank. Deleting it");
           delete data[key]
        }
    }

Answer 2

Can't you do this? Or am I missing something?

Object.entries(data).filter(([k,v],i)=>!!v)

give you this:

"[
    [
        "name",
        "John"
    ],
    [
        "externalId",
        2548
    ],
    [
        "email",
        "[email protected]"
    ]
]"

!! will turn a value into boolean, at that stage you filter out null,NaN and undefined. Indeed, if you want to try this on nested objects, then you have to recursively do this because !!Object() is always true. Even better would be to recursively and asynchronously copy the object, filter out falsey primitives and pass a callback to stringify in the end.

Edit:

Someone below mentioned some falsey values that you might want to keep such as 0. In that case chain them:

v===null || v===0 || !!v //null, 0 and anything not falsey, but not undefined etc.