JavaScript：使用专用函数还是带有参数的通用函数？

Question

I wonder which approach is better for creating functions in JavaScript classes:

1. Having a list of functions each dedicated to one specific operation.
2. Having a general purpose function that takes arguments to decide what to execute.

My belief is the first option provides a nice interface but may cause redundant code, and second option is clean and flexible but may become confusing to use.

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I really did not know how to ask this question, so I would like to explain it by a code example.

Suppose we have these Classes for printing names of creatures.

class GeneralPurposePrint {
  constructor (args) {
    this.isHuman = args.isHuman || false;
    this.isOld = args.isOld || false;
    this.name = args.name || "Nameless" 
  }

  //This is what I mean by "general purpose function"
  //arguments may as well come with the printName functions...
  printName(){
    const type = this.isHuman ? "the human" : "the animal";
    const age = this.isOld ? "Old" : "Young";

    console.log(`${age} ${this.name} ${type}`)
  }
}


class DedicatedPrint {
  constructor (name) {
    this.name = name;
  }

  //And by dedicated functions I mean the following functions here
  printOldHuman() {
    console.log("Old human", this.name, "the human")
  }

  printYoungHuman() {
    console.log("Young", this.name, "the human")
  }

  printOldAnimal() {
    console.log("Old", this.name, "the animal")
  }

  printYoungAnimal() {
    console.log("Young", this.name, "the animal")
  }
}

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This question is out of pure curiosity and maybe it's best to use both of the approaches. And please don't mind the funky code example I wrote, you may think of the similar structure for a class for choosing a sorting algorithm, a type of connection, creating a shape or such.

Answer 1

Thats rather a design decision, so you should ask yourself does GeneralPurposePrint really get old or is it really sometimes human and sometimes not? If not that definetly shouldn't be properties of the class. To reduce the redundant code of the second approach you could just pass in arguments to the method:

printName(old, human) {
  console.log((old ? "Old" : "Young") + this.name + (human ? "the human" : "the animal"));
}