What is the difference between class properties and local variables inside methods?

Class properties (fields) and local variables inside methods differ in several key aspects:

• Scope:

  • Class properties are accessible in all methods of the class (depending on access modifiers).
  • Local variables are only visible within the block or method where they are declared.

• Lifetime:

  • Properties exist as long as the object (or class, if the field is static) exists.
  • Local variables are created when the method is called and destroyed when it exits.

• Initialization:

  • Class properties are assigned default values (e.g., 0 for numbers, null for objects) if not explicitly initialized.
  • Local variables must be explicitly initialized before use; otherwise, the compiler will generate an error.

Example:

public class Example {
    private int field; // class property

    public void method() {
        int localVar = 10; // local variable
        System.out.println(field);    // accessible
        System.out.println(localVar); // accessible
    }
}