background
Interviewer: Hello, please implement a deep copy with TS
Little A: Good deep copy:
- There are different types
- And you have to recurse
TS:
- Some higher-order usage is needed
code
const deepCopy = <T>(target: T): T= > {
if(target === null) {
return target
}
if(target instanceof Date) {
return new Date(target.getTime()) as any
}
if(target instanceof Array) {
const cp = [] as any[]
(target as any[]).forEach(v= > cp.push(v))
return cp.map((n: any) = > deepCopy<any>(n)) as any
}
if(typeof target === 'object'&& target ! = = {{})
constcp = {... (targetas {[key: string] :any})} as { [key: string] :any }
Object.keys(cp).forEach(k= > {
cp[k] = deepCopy<any>(cp[k])
})
return cp as T
}
}
Copy the codeconclusion
- Null, Date, Array, object
- In the case of Array and Object, values also need to be deepCopy, that is, recursive negative values