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javascript push associative array in another

I have two associative arrays and want to push one completely to the other.
my current code:
LT_WORK_PACKAGE.data[i].STOCK_DOCCAT = stock_data.STOCK_DOCCAT;
LT_WORK_PACKAGE.data[i].STOCK_DOCNO = stock_data.STOCK_DOCNO;
LT_WORK_PACKAGE.data[i].STOCK_ITMNO = stock_data.STOCK_ITMNO;
im looking for something like this:
LT_WORK_PACKAGE.data[i].push(stock_data);

.push is for adding items to an array. You do have an object , and to copy multiple properties into an object,you can use Object.assign:
Object.assign(
/*to:*/ LT_WORK_PACKAGE.data[i],
/*from:*/ stock_data
);

You can use LT_WORK_PACKAGE.data[i] = stock_data.
Note that the previous content (if it exists) of LT_WORK_PACKAGE.data[i] will be replaced by a reference to stock_data. Any changes made in stock_data will be done in LT_WORK_PACKAGE.data[i] If you want a copy, you can use : LT_WORK_PACKAGE.data[i] = JSON.parse(JSON.serialize(stock_data))

Iterate over array of object using map till the second last object

I am having an array of objects where all objects have the same keys except the last object. Think like array have values and to denote all these values as a whole I have a key I am pushing the key at last along with the values in the array.
homeTask is a list of object which is the values and homeTaskKey is the key to represent the homeTask
res.data.resultSet.homeTask.forEach(element => {
var singleEvent={
task:'',
taskDuration:'',
status:'',
};
singleEvent.task=element.task;
singleEvent.taskDuration=element.taskDuration;
singleEvent.status=element.status;
newEvents.push(singleEvent);
});
newEvents.push(res.data.resultSet.homeTaskKey);
addEvent(newEvents);
}
addEvent is props method of parent component where I am setting the array to state variable name as events which is array type.
When I iterate over events using map I want to skip the last object since it does not have keys like task, taskDuration and status. Therefore it won't give any problem when I fetch those values.

events.slice(0, events.length-1).map(<function>);
this will ignore the last element and all n-1 entries will be fed to map
UPDATE:
the array name is events not event therefore it should be events.length

You could still use map, but simply pop the last element off once the map completes. For example:
const newEvents = homeTask.map(({ task, taskDuration, status }) => ({
task, taskDuration, status
}))
newEvents.pop()
addEvent(newEvents)
Or just replace the last item with your taskkey, as you know the last item will be junk:
newEvents[newEvents.length - 1] = res.data.resultSet.homeTaskKey
Or just slice the array prior to mapping, and then push the taskKey at the end like you were doing. slice is safe to perform on your prop, as it shallow copies.
Or most importantly, ask yourself why you have this entirely weird data structure that has the key appended on the end. Perhaps rethink your data and not create this problem for yourself in the first place.

res.data.resultSet.homeTask.forEach((element,index) => {})
second param to function is index you, can use this to identify the second last element by comparing it with total length of array.

hmm you can try with this
res.data.resultSet.homeTask.forEach(element => {
if(!element.task)
return false;
...bla bla bla
}

The map() method creates a new array with the results of calling a function for every array element.
So it creates an array of same length from source array.
What you need is filter()
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
Something like this;
const tasks = res.data.resultSet.homeTask.filter((element) => {
const { task, taskDuration, status } = element;
return task && taskDuration && status;
});

Replacing array elements in Javascript produces unexpected results

I'm trying to replace array elements (generic objects) with their alternatives (specific Objects), but objects within the original array remain unchanged.
class SpecificObject{
}
this.Objects = [{},{}];
this.Objects.map((signer,index) => {
//convert json generics to js objects
this.Objects[index] = new SpecificObject(signer);
});
console.log(this.Objects);
Not sure if the code snippet illustrates the problem correctly, but what i expect to see is:
[
SpecificObject{},
SpecificObject{}
]
I even tried cloning the original object to do the iteration but it didn't help. Must be missing something stupid. Is there a way to achieve what i need with lodash?
Edit(followed the answer advise):
Now i do the following:
console.log('signers-before', this.Signers);
this.Signers.map(signer => new SigningTableSigner(signer));
console.log('signers-after',this.Signers);
And this is what i get in my log(object still remain generic):
Edit2
Oops, i forgot the assignment. this.Signers =
now like this everything works as expected:
console.log('signers-before', this.Signers);
this.Signers = this.Signers.map(signer => new SigningTableSigner(signer));
console.log('signers-after',this.Signers);

There is no need to modify the collection while you are iterating it. Just return the object from the map.
this.Objects = this.Objects.map((signer,index) => new SpecificObject(signer));

Map is used when you wants to return an array. You can just use forEach for what you are trying to do. But I think this will look better
this.Objects = this.Objects.map(signer => new SpecificObject(signer))

You don't use map correctly. You should be just returning objects inside arrow functions. map actually returns new array, which contains elements which were created by applying function you have provided. Because of that you also have to reassign result ot this.Objects.
this.Objects = this.Objects.map(signer => {
//convert json generics to js objects
return new SpecificObject(signer);
})

Pushing key-value pairs and using them without indices

Can I somehow push the key:vale pairs to a JavaScript array so that I can later use them without indices even if I don't know what order I'll grab them in? I mean, such code would work:
var test = [];
test.push({key1: 5});
test.push({key2: 7});
console.log(test[0].key1);
But let's say I don't always receive the keys in that order and would like the last line to just be console.log(test.key1);, without the need to index it. Can I somehow push the pairs in such a way that later I only need to specify the key for which I want a value, and not an index under which it resides?

Yes...
var test = {};
test.key1 = 5;
test.key2 = 7;

instead of push, use an object and assing key1 to that like this: test.key1 = 5
but now it can't work as array

After using push(), array is logged as a number

I'm trying to get an array of some images to flip through. The first set need to be in descending order, while the second set need to be in ascending order, so I have written this:
var flipArray = [];
function createFlipArray(older, newer){
flipArray = $("#"+older).children();
flipArray = flipArray.get().reverse();
flipArray = flipArray.push($('#'+newer).children());
console.log(flipArray);
loopThroughImages();
}
When I push the second set onto the first set, it logs the array as 4, even though there are 6 items in the whole array.
If I log the array after I populate it with the older children, it returns with HTML objects, which I expect to see after I push the newer children on.
Any suggestions?

.push modifies the array in-place. It does not return a new array, it returns the array's new length.

Array.prototype.push returns the array's new length. It modifies the original array. Remove the flipArray = before it.