Variable scope is the range of code where a variable is visible and can be referenced. In JavaSE, there are four types of variable scope: class, instance, method, and block.

In this article, he dives into Local Variable Type Inference. Java SE 10 (March 2018) introduced type inference for local variables. Java Language Architect Brian Goetz explains the feature. BT.

Tip: Unlike class and instance field variables, threads cannot share local variables and parameters. The reason: Local variables and parameters allocate on a thread’s method-call stack.