了解评估参考 [英] Understanding Eval Reference

问题描述

我知道关于此主题还有其他话题，但我再次询问是因为我确实在努力理解评估以及如何正确使用它，以便它不会变成邪恶.通过查看此代码，如何获取console.log(this.arrTest);记录['Back to Original']?我尝试了许多变体，但没有一个起作用.

I know that there are other threads on this topic but I am asking again because I am really trying hard to understand eval and how to use it correctly so that it doesn't become evil. By looking at this code, how can I get the console.log(this.arrTest); to log ['Back to Original']? I tried many variations and none of them work.

我不想要此解决方案，请:this.TestClass.Run.call(this, "this.arrTest = ['Back to Original'];");我要在课程级别内使用解决方案.

I do not want this solution please: this.TestClass.Run.call(this, "this.arrTest = ['Back to Original'];"); I want a solution inside the class level.

这里是一个有角的闪电战，可以玩: https://stackblitz.com/edit/angular-mtuvvz?file=src%2Fapp%2Fapp.component.ts

Here is an angular blitz to play with: https://stackblitz.com/edit/angular-mtuvvz?file=src%2Fapp%2Fapp.component.ts

export class AppComponent  {
  arrTest = ['Original'];

  constructor() {
    this.TestClass.Run("this.arrTest = ['Back to Original'];");
    console.log(this.arrTest);
  };

  TestClass = {
    Run : (pString) => {
      this.arrTest = ['Changed']; //So this works

      eval(pString); //Why is this not working
      eval.call(this, pString); //Why is this not working
      eval.call(null, pString); //Why is this not working
      (1, eval)(pString); //Why is this not working
      (eval)(pString); //Why is this not working
      var my_eval = eval; //Why is this not working
      my_eval(pString); //Why is this not working
    }
  };

}

我已经阅读了这两篇文章，但我不理解它们的解决方案:

I have read both of these articles but I don't understand a solution from them:

http://2ality.com/2014/01/eval.html

http://blog.klipse.tech /javascript/2016/06/20/js-eval-secrets.html

推荐答案

所以这在我的场景中很好地解决了这个问题:

So this solves the problem quite well in my scenario:

export class AppComponent  {
  arrTest = ['Original'];

  constructor() {
    this.TestClass.Run("arrTest", "['Back to Original']");
    console.log(this.arrTest);
  };

  TestClass = {
    Run : (pKey, pValue) => {
      this.arrTest = ['Changed']; //So this works

      this[pKey] = pValue;
    }
  };

}

这篇关于了解评估参考的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！