Java Scope
Java Scope
In Java, variables are only accessible inside the region they are created. This is called scope.
Method Scope
Variables declared directly inside a method are available anywhere in the method following the line of code in which they were declared:
Example
public class Main { public static void main(String[] args) { // Code here CANNOT use x int x = 100; // Code here can use x System.out.println(x);
}}
Block Scope
A block of code refers to all of the code between curly braces {}
.
Variables declared inside blocks of code are only accessible by the code between the curly braces, which follows the line in which the variable was declared:
Example
public class Main {
public static void main(String[] args) {
// Code here CANNOT use x
{ // This is a block
// Code here CANNOT use x
int x = 100;
// Code here CAN use x
System.out.println(x);
} // The block ends here
// Code here CANNOT use x
}
}
A block of code may exist on its
own or it can belong to an if
, while
or for
statement. In the case of for
statements,
variables declared in the statement itself are also available inside the block's scope.