在JavaScript中使用eval()的主要好处是什么? [英] What's the main benefit of using eval() in JavaScript?

问题描述

我知道这可能是一个新手问题，但是我对eval()的主要好处感到好奇-最好在哪里使用它?我感谢任何信息.

I know this may be a newbie question, but I'm curious as to the main benefit of eval() - where would it be used best? I appreciate any info.

推荐答案

最好使用eval函数:永不.

其目的是将字符串评估为Javascript表达式.示例:

It's purpose is to evaluate a string as a Javascript expression. Example:

eval('x = 42');

它已经被使用了很多次，因为很多人不知道如何为他们想做的事情编写正确的代码.例如，当为字段使用动态名称时:

It has been used a lot before, because a lot of people didn't know how to write the proper code for what they wanted to do. For example when using a dynamic name for a field:

eval('document.frm.'+frmName).value = text;

做到这一点的正确方法是:

The proper way to do that would be:

document.frm[frmName].value = text;

由于eval方法将字符串作为代码执行，因此每次使用该字符串都可能使某人有可能在页面中注入有害代码.请参阅跨站点脚本.

As the eval method executes the string as code, every time that it is used is a potential opening for someone to inject harmful code in the page. See cross-site scripting.

eval函数有一些合法用途.但是，您不太可能会遇到实际需要它的情况.

There are a few legitimate uses for the eval function. It's however not likely that you will ever be in a situation where you actually will need it.

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