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.
How We Evaluate Bluetooth Speakers. To evaluate each Bluetooth speaker, we listen to a wide range of music and test the device's durability, if applicable. We also test speakerphone capabilities (if available) and play tunes continuously to see how long the speakers' batteries last. We also consider the quality of the design and ease of use and setup.