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Update deepClone.md

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Angelos Chalaris
2020-09-04 19:33:19 +03:00
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parent e24194c8b9
commit de3832092d
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snippets/deepClone.md
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@ -4,11 +4,13 @@ tags: object,recursion,intermediate
--- ---
Creates a deep clone of an object. Creates a deep clone of an object.
Clones primitives, arrays and objects, excluding class instances.
Use recursion. Use recursion.
Check if the passed object is `null` and, if so, return `null`. Check if the passed object is `null` and, if so, return `null`.
Use `Object.assign()` and an empty object (`{}`) to create a shallow clone of the original. Use `Object.assign()` and an empty object (`{}`) to create a shallow clone of the original.
Use `Object.keys()` and `Array.prototype.forEach()` to determine which key-value pairs need to be deep cloned. Use `Object.keys()` and `Array.prototype.forEach()` to determine which key-value pairs need to be deep cloned.
If the object is an `Array`, set the `clone`'s `length` to that of the original and use `Array.from(clone)` to create a clone.
```js ```js
const deepClone = obj => { const deepClone = obj => {
@ -17,11 +19,11 @@ const deepClone = obj => {
Object.keys(clone).forEach( Object.keys(clone).forEach(
key => (clone[key] = typeof obj[key] === 'object' ? deepClone(obj[key]) : obj[key]) key => (clone[key] = typeof obj[key] === 'object' ? deepClone(obj[key]) : obj[key])
); );
return Array.isArray(obj) && obj.length if (Array.isArray(obj)) {
? (clone.length = obj.length) && Array.from(clone) clone.length = obj.length;
: Array.isArray(obj) return Array.from(clone);
? Array.from(obj) }
: clone; return clone;
}; };
``` ```