it doesnt............u have to get it from other game.by trading
Golbat will evolve if it has max friendship with its trainer which means it can evolve at any level.
To evolve Golbat, you have to have a high friendship level. So have Golbat in the front of your party and fight with it. When it faints, its friendship will go down. So just use it to fight a lot. You might also want to equip Golbat with a Soothe Bell. It increases the friendship between you and your pokemon.
There is no specific level for golbat to evolve it needs to be loyal to it's trainer in order to evolve.
Golbat is a happiness evolution so it can evolve at any level.
It evolves at level 22 into Golbat. Golbat evolves with happiness into Crobat.
Make a Golbat level up on a high friendship level.
golbat can evolve at any level if its friendship is up to max power...or...it can evolve if you give it a berry that gets the Pokemon friendlier then get it one level higher and ... evolution
Golbat doesn't evolve at any specific level because it takes a trainers love to there Golbat in order for it to evolve it can be level 100 when it evolves or it can evolve the next level right after it becomes a Golbat it all depends on it's happiness with it's trainer.
Happiness maxed
it evolves with friendship
Level 20.
Golbat evolves into Crobat with happiness not a specific level, and why are you asking for the level in the Sapphire game while your question is in the Heartgold and Soulsilver category???