How to get console.log output from eval()?

问题

I am using eval() to run a script from a string. Below is the code:

eval('console.log("hello")');

I will get hello from the console output. I wonder whether I can save the hello into an variable in the current context. So I am looking for something like this:

const output = eval('console.log("hello")'); // I expect the console output is returned from eval() function.

But I get an undefined response. Is there a way for me to do that?

回答1:

It is impossible because console.log() only returns undefined, however you can make a function that will return something.

Example:

console.oldLog = console.log;
console.log = function(value)
{
    console.oldLog(value);
    return value;
};

const output = eval('console.log("hello")');

Hope this will help.

来源：https://stackoverflow.com/questions/46417440/how-to-get-console-log-output-from-eval