diff --git a/snippets/deepClone.md b/snippets/deepClone.md index a0da1f0a5..ced6cec4a 100644 --- a/snippets/deepClone.md +++ b/snippets/deepClone.md @@ -3,12 +3,14 @@ title: deepClone 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. 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.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 const deepClone = obj => { @@ -17,15 +19,15 @@ const deepClone = obj => { Object.keys(clone).forEach( key => (clone[key] = typeof obj[key] === 'object' ? deepClone(obj[key]) : obj[key]) ); - return Array.isArray(obj) && obj.length - ? (clone.length = obj.length) && Array.from(clone) - : Array.isArray(obj) - ? Array.from(obj) - : clone; + if (Array.isArray(obj)) { + clone.length = obj.length; + return Array.from(clone); + } + return clone; }; ``` ```js const a = { foo: 'bar', obj: { a: 1, b: 2 } }; const b = deepClone(a); // a !== b, a.obj !== b.obj -``` \ No newline at end of file +```