I have two objects which I am comparing. I have an array of objects, and I am trying to see if the array contains a certain object. I think it should be finding it, but it is not. Here is the object in the array:
and here is the object I am looking for:
I am using:
if (collection.indexOf(object) !== -1) {
//do something
}And it returns an index of -1, even though it seems to me that the objects match. Am I missing something here?
try this, if all fields are equals return true
function testContains(arrayOfObject, lookingObject )
var index;
for (index = 0; index < arrayOfObject.length; ++index) {
var o = arrayOfObject[index]);
if(JSON.encode(o)===JSON.encode(lookingObject)) {
return true;
}
}
return false;
}
indexOf() will work only for elementary types like numbers, strings, boolean etc. It does not do deep comparison to match objects.
Something like the following should work:
var found = false;
arr.forEach(function(_object) {
// code to set found to true if _object is what you need
});
// if found is true, your array has your object, else it doesn't
some() before. But it does looks like a better fit in this case.If you can use Lodash (it's really useful and worth it in my opinion) you can use _.find:
_.find(collection, object)
or if you want to only know if the object is present in array, you can do:
_.includes(collection, object)
I optimized @Kaiser'S answer into a one-liner:
var found = obj_list.map(JSON.stringify).indexOf(JSON.stringify(obj)) !== -1;
But, this will only work, if the order of the objects is the same:
The JSON represantation of obj1 = {'a': 1, 'b': 2} wouldn't match obj2 = {'b': 2, 'a': 1}
But if the object you're looking for was copied from the list then the test should work.
Also to take into account, this will only work if the objects in the list are simple objects which can be "stringified".
indexOf()will work only for elementary types like numbers, strings, boolean etc. It does not do deep comparison to match objects.