[Vuejs]-On emitting an object, all items of object getting pushed in all arrays

You shouldn’t directly manipulate a property in a component.

It seems your paymentEntry is passed to the parent as a property. Either hold a local copy, manipulate that and then update or look into the .sync modifier for properties (https://v2.vuejs.org/v2/guide/components-custom-events.html#sync-Modifier) if you’re sure this is what you want to do.

Also push was the right way to go.