final --> for primitives --> value can't change. for non-primitives --> you can't change the reference and point it to another object. Note : It is different from immutability.
Hands down, the Bluetooth speaker with the longest battery life is the Fugoo. It offers up to 40 hours of battery life, nearly twice the battery life of other leading Bluetooth speakers in this category. Given how long its battery lasts, you might even forget that the Fugoo needs to be plugged in to charge.
Jawbone Era ($64) With the second-longest standby time (200 hours), the Jawbone Era is No. 2 on the list. The headset has a sleek design and is great for canceling out background noise for optimal voice quality. The Bluetooth headset can be paired with eight different devices and has a talk time of five hours.