write your own extends in es5

Question

I believe you've used extends keyword in you JavaScript programs before.

Could you implement a myExtends() function in ES5 to mimic the behavior of extends?

myExtends() takes a SubType and SuperType, and return a new type.

const InheritedSubType = myExtends(SuperType, SubType)

const instance = new InheritedSubType()

// above should work (almost) the same as follows

class SubType extends SuperType {}
const instance = new SubType()

To solve this problem, you need to fully understand what is Inheritance

note

Your code will be test against following SuperType and SubType

function SuperType(name) {
    this.name = name
    this.forSuper = [1, 2]
    this.from = 'super'
}
SuperType.prototype.superMethod = function() {}
SuperType.prototype.method = function() {}
SuperType.staticSuper = 'staticSuper'

function SubType(name) {
    this.name = name
    this.forSub = [3, 4]
    this.from = 'sub'
}

SubType.prototype.subMethod = function() {}
SubType.prototype.method = function() {}
SubType.staticSub = 'staticSub'

Code

const myExtends = (SuperType, SubType) => {
  // your code here
}

Source

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