如何重构这个多嵌套if else块

时间:2015-07-17 22:53:34

标签: javascript if-statement refactoring data-driven

我有这种多嵌套的if-else块。我的理解是,有一个数据驱动的'这种方法可以帮助消除对它的需求并减少代码,但是,我还没有很大的经验,所以任何人都可以帮助我重构这些代码来处理数据 - 从动'进场?

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;
    }
  }
}

1 个答案:

答案 0 :(得分:2)

非常确定你的逻辑归结为:

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;   
    }
}

你应该注意的事项:

此:

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

永远不会是正确的。不要创建空块,改变你的表达方式,如下所示:

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

你重复这段代码3次。保持干燥(不要重复自己)

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

如果您注意到您正在重复这样的代码,请退后一步,看看如何更改逻辑流程,以便您只需编写一次代码。