Merge

Merges multiple objects into a single new object. Properties from later arguments override properties from earlier arguments (shallow merge).

Syntax

Merge(object1, object2, ...)

Parameters

object1, object2, … (objects): Two or more objects to merge. Non-object arguments are silently skipped.

Returns

object: A new object containing all properties from the input objects

Description

The Merge function combines multiple objects into a single new object. Properties from later arguments override properties from earlier arguments when there are key conflicts. This is a shallow merge - nested objects are not recursively merged but replaced entirely.

The function is variadic and accepts any number of arguments. Non-object arguments (strings, numbers, arrays, null) are silently skipped.

Examples

Basic merge

var obj1 = { "a": 1, "b": 2 }
var obj2 = { "c": 3, "d": 4 }

var merged = Merge(obj1, obj2)
# merged is { "a": 1, "b": 2, "c": 3, "d": 4 }

Override semantics

var defaults = { "theme": "light", "language": "en", "notifications": true }
var userPrefs = { "theme": "dark", "language": "es" }

var settings = Merge(defaults, userPrefs)
# settings is { "theme": "dark", "language": "es", "notifications": true }

Multiple objects (variadic)

var base = { "a": 1 }
var overrides1 = { "b": 2 }
var overrides2 = { "c": 3 }

var result = Merge(base, overrides1, overrides2)
# result is { "a": 1, "b": 2, "c": 3 }

Order matters for conflicts

var obj1 = { "x": 1 }
var obj2 = { "x": 2 }
var obj3 = { "x": 3 }

var result = Merge(obj1, obj2, obj3)
# result is { "x": 3 } (last value wins)

Creating object copies

var original = { "name": "Alice", "age": 30 }
var copy = Merge(original)

copy.name = "Bob"
# original.name is still "Alice"
# copy.name is "Bob"

Non-object arguments are skipped

var obj1 = { "a": 1 }
var obj2 = { "b": 2 }

var result = Merge(obj1, "string", null, 42, obj2)
# result is { "a": 1, "b": 2 } (non-objects ignored)

Shallow merge behavior

var obj1 = { "nested": { "a": 1, "b": 2 } }
var obj2 = { "nested": { "c": 3 } }

var result = Merge(obj1, obj2)
# result is { "nested": { "c": 3 } }
# Note: obj1's nested object is replaced, not merged

Building configuration objects

var systemDefaults = {
    "timeout": 30000,
    "retries": 3,
    "debug": false
}

var environmentConfig = {
    "debug": true,
    "apiUrl": "https://api.example.com"
}

var userOverrides = {
    "timeout": 60000
}

var config = Merge(systemDefaults, environmentConfig, userOverrides)
# config is {
#     "timeout": 60000,
#     "retries": 3,
#     "debug": true,
#     "apiUrl": "https://api.example.com"
# }

Adding properties to an object

var user = { "id": 1, "name": "Alice" }
var timestamp = { "createdAt": Now() }
var metadata = { "version": "1.0" }

var enriched = Merge(user, timestamp, metadata)
# enriched has all properties from user, timestamp, and metadata

Empty merge

var result = Merge()
# result is {} (empty object)

Notes

Creates a new object (does not mutate input objects)
Later arguments override earlier arguments for conflicting keys
Shallow merge only - nested objects are replaced, not recursively merged
Non-object arguments are silently skipped
With zero arguments, returns an empty object
With one argument, returns a shallow copy of that object
Order of arguments determines override priority (last wins)
Useful for applying configuration defaults, creating copies, and combining partial objects