Nothing like biased based wikipedia
.
That's more than a little childish and unwarranted, but I'm sure you do your best.
Since you feel compelled to dismiss Wikipedia, let me suggest that you find a copy of Udo Schnelle's
Schnelle addresses the question at hand in section
8.4. The First Letter of John.
At the end of section
8.4.2 Author, he summarizes ...
Language, the world of theological concepts presupposed, and the different situation point to the conclusion that 1 John and the Gospel are by different authors. [page 456; emphasis in the original - JS]
Then, at the end of the subsequent section
8.4.3 Place and Time of Composition, he concludes ...
1 John was thus probably written before the Gospel, but after 2-3 John. We may take the time of writing to be ca. 95 CE, and again consider Ephesys, the locus of the Johannine school as its probable point of origin. Papius knew 1 John (cf. Eusebius HE 3.39.17), which is documented for the first time in Polycarp (cf.1 John 4.2 and Polycarp Phil. 7.2). [page 459]
I hope this helped.