浏览器开发者工具使用之复制旧变量的值

It’s not uncommon for me to run a command in the console, then realise I forgot to capture the result so I could run it through a map or some such process.

This is where $_ is a live saver, which contains the result of the last command run in the console.

In the example below, I’ve forgotten to capture the result of the promise so I can manipulate (or in this case, copy) the result. This is simply fixed by running a new command with $_.then(…​).