# JavaScript (ES6), 30 bytes

 +alert((({alert}+{alert}+{})))

Outputs `[object Object][object Object][object Object]`.

Works by creating three objects:

* the first two are of the form `{ "alert" : alert }` using ES6 notation `{alert}`

* the third is a simple empty object

Then it uses `+` to concatenate them together, and all three have an identical expression as a string, `[object Object]`.

The leading `+` is useless, only present to fill out the number of `+` characters, but is harmless to the output of the program.