如何重构这个多嵌套的 if else 块

Question

我有这种多嵌套的 if-else 块。我的理解是，有一种 'data-driven' 方法可以帮助消除对它的需求并 trim 降低代码，但是，我还没有在很大程度上使用它，所以任何人都可以提供帮助我重构此代码以在 'data-driven' 方法中工作？

function (arg1) {
  if(this.thing[arg1]){
    // there is a valid property for this arg1
    if(this.thing.a){
      // there exists an 'a' propertie also
      if(this.thing.a.arg1 == arg1){
        // the a property has a property is the same as the arg1    
        // if this 'a' has a number higher than 0, avoid doing anything
        if(this.thing.a.number > 0){
        }else{
          // 'a' number was 0 or lower, so we do something
          this.thing.a = this.thing[arg1];
          this.thing.a.arg1 = arg1;
        }
      }else{
        // the' a' is not the arg1
        // so we want to use the current arg1!
        // but only if its 'number' is lower than 1
        if(this.thing.a.number > 0){
        }else{
          // 'a' number was 0 or lower, so we do something
          this.thing.a = this.thing[arg1];
          this.thing.a.arg1 = arg1;
        }
      }
    }else{
      // there is no thing.a so we set it to arg1 
      this.thing.a = this.thing[arg1];
      this.thing.a.arg1 = arg1;
    }
  }
}

Answer 1

很确定您的逻辑归结为：

if (this.thing[arg1]) {
    //confirm or set a
    this.thing.a = this.thing.a ? this.thing.a : this.thing[arg1];

    //if a.arg1 is not thing[arg1] and a.number is less than 1
    if (this.thing.a.arg1 !== this.thing[arg1] && this.thing.a.number < 1) {
        this.thing.a = this.thing[arg1];
        this.thing.a.arg1 = arg1;   
    }
}

注意事项：

这个：

if(someNumber > 0){
   //do nothing
} else {
   //do something
}

永远不会是对的。不要创建空块，改变你的表达方式，像这样：

if (someNumber < 1) {
    //do something
}

您重复此代码块 3 次。保持干爽（不要重复自己）

this.thing.a = this.thing[arg1];
this.thing.a.arg1 = arg1;

如果您发现自己在重复这样的代码，请退后一步，看看如何更改您的逻辑流程，这样您只需编写一次代码。

如何重构这个多嵌套的 if else 块

how to refactor this multi-nested if else block

javascript

if-statement

refactoring

data-driven