What is the difference between scope and block?

Question

I saw a piece of code in a book, which is as follows:

x = 10;
if(x ==10) { // start new scope
int y = 20; // known only to this block
x = y * 2;
}
         


        

Answer 1

From the Java language specification:

14.2. Blocks:

A block is a sequence of statements, local class declarations, and local variable declaration statements within braces.

6.3. Scope of a Declaration

The scope of a declaration is the region of the program within which the entity declared by the declaration can be referred to using a simple name, provided it is visible (§6.4.1).

In a block, you can declare variables. A scope defines the region, where you can access a declared variable by its simple name.