Check if javascript object is inside an existing array

Question

I'm wanting to know how to check if an object still exists in an array

var a = [{ "id": 1, "name": "Jeffery" }, { "id": 2, "name": "Jimmy" }]

I'm trying to find if Jeffery is still in this array:

var obj = { "names": { "Jeffery": { "age": 43, "job": "Doctor" }, "Jimmy": { "age": 23, "job": "Developer" } } };

I've attempted to use this code which brings no luck. Am I doing anything wrong?

function contains(a, obj) {
    for (var i = 0; i < a.length; i++) {
        if (a[i] === obj) {
            return true;
        }
    }
    return false;
}

please add the data of `obj` as well. small hint: you compare strict with an object. — Nina Scholz, Dec 17 '16 at 10:22
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes — RomanPerekhrest, Dec 17 '16 at 10:22
your question is unclear, elaborate the relation between `a` and `obj` variables — RomanPerekhrest, Dec 17 '16 at 10:28
`a` = array that I want to search with and `obj` is the array I want to search for — irrational, Dec 17 '16 at 10:31
what do you expect as outcome? a single check of the first name only? all names? — Nina Scholz, Dec 17 '16 at 10:32
I just want to return `true` or `false` to whether if `Jeffery` still exists in the `obj` array. — irrational, Dec 17 '16 at 10:33
you given an array with two objects and an object with name as property with two properties. which would you like to test against? — Nina Scholz, Dec 17 '16 at 10:37
Do you mind writing out an answer, you're making no sense to me. — irrational, Dec 17 '16 at 10:37
for me, it is not clear, in which direction you like to check. a) with given string `Jeffery` in `a` or b) with given string `Jeffery` in `obj`? — Nina Scholz, Dec 17 '16 at 10:46
Possible duplicate of [How do I check if an array includes an object in JavaScript?](http://stackoverflow.com/questions/237104/how-do-i-check-if-an-array-includes-an-object-in-javascript) — byxor, Dec 17 '16 at 11:59

score 2 · Accepted Answer · answered Dec 17 '16 at 10:51

You could use the in operator for a check of a property in an object.

The in operator returns true if the specified property is in the specified object.

function contains(name, obj) {
    return name in obj.names;
}

var obj = { names: { Jeffery: { age: 43, job: "Doctor" }, Jimmy: { age: 23, job: "Developer" } } };

console.log(contains('Jeffery', obj));
console.log(contains('Foo', obj))

score 0 · Answer 2 · answered Dec 17 '16 at 11:10

With the function contains you can check the desired name: 'Jeffery' is in the the object and also in the array:

var a = [{ "id": 1, "name": "Jeffery" }, { "id": 2, "name": "Jimmy" }],
    obj = { "names": { "Jeffery": { "age": 43, "job": "Doctor" }, "Jimmy": { "age": 23, "job": "Developer" } } };

function contains(name, a, obj) {
    return obj.names[name] && a.filter(o => o.name === name) ? true : false;
}

console.log(contains('Jeffery', a, obj));
console.log(contains('Jimmy', a, obj));
console.log(contains('Foo', a, obj));

Check if javascript object is inside an existing array

2 Answers2

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