How do you clone an array of objects in JavaScript?
Deep Cloning an array of objects (all nested objects get fully duplicated) is done using JSON.parse
with JSON.stringify
:
For a Shallow Copy (only the array is new, the objects are the same old buddies you know), the spread operator ...
is friendly:
The JSON
methods say "heck no!" to functions or circular refs; for such complexity, use Lodash's _.cloneDeep
:
Ascend to the cloning Master Level
Circular References: Round and Round we clone!
For arrays with objects having circular references, the swanky structuredClone
function is just what you need:
Bear in mind, it's a newbie API, so a polyfill might come in handy for older browser compatibility.
Run Forest, Run: Performance Mass vs. Class
For performance fans, structuredClone
and JSON
are more of long-distance runners when deep copying. Need speed over terrain? Use spread operator and .map()
for quick cloning of shallow objects:
Object.assign: Shallow but Fast
If cloning an array with only shallow objects, Object.assign
mixed with .map()
does the trick:
Need a simple array clone double-quick? .slice(0)
gets you a quick shallow copy:
Libraries and the Magic Wand
Got complex data structures? Bring in the heavy artillery like Immutable.js or craft your own custom cloning functions to nix recursion issues.
The art of Swift and Deep (Copy)
Ground zero is knowing the difference between deep and shallow copying. Shallow copy is enough when nested objects are just spectator. But, when the game requires a full object tree duplication, deep copying comes into play.
Choose your Cloning Power Ring
While choosing a cloning method, weigh in browser support and data structure's complexity. The right method is a balancing act between performance, compatibility, and the type of objects queued up for cloning.
Shooting Cloning Pitfalls from the Sky
When cloning, track mutable object references like a hawk. Misunderstanding this can drop bugs where one copy’s changes crash land on the other. Also, guard against "too much recursion" errors by smartly avoiding deep copy of huge or complex object architectures.
Custom Cloning: Your Cup of Tea
In specific scenarios, a custom cloning method gives an edge. Here's a custom built clone function that can handle many scenarios, including circular references, functions, and stubbornly non-JSON-serializable objects.
When to Surf Shallow
If the clones aren't set to change, a shallow copy might be all you need. It can save significant processing energy and memory like a power-saving lightbulb.
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