Final (Java): Difference between revisions

Revision as of 15:51, 7 July 2025

Latest revision as of 16:08, 25 August 2025

(3 intermediate revisions by 2 users not shown)

Line 10:

Example:

<syntaxhighlight lang="java">

public final class MyFinalClassFinalClass {...}

// ...

}

// Forbidden

public class ThisIsWrong extends MyFinalClass {...} // forbidden

public class DerivedClass extends FinalClass {

// ...

}

</syntaxhighlight>

Line 21 ⟶ 26:

Example:

<syntaxhighlight lang="java">

public class Base {

public final void m2m1() { ... }

{

public final void m1m2() { ... }

public final void m2() {...}

public static void m3() { ... }

public static final void m4() { ... }

}

public class Derived extends Base {

public void m2m1() { ... } // forbiddenOK, overriding Base#m1()

{

public void m1m2() { ... } // OK, overriding Base#m1()forbidden

public void m2() {...} // forbidden

public static void m3() { ...} } // OK, hiding Base#m3()

public static void m4() { ...} } // forbidden

}

</syntaxhighlight>

Line 53 ⟶ 56:

public class Sphere {

// piPi is a universal constant, about as constant as anything can be.

public static final double PI = 3.141592653589793;

Line 62 ⟶ 65:

Sphere(double x, double y, double z, double r) {

radius = r;

xPos = x;

yPos = y;

zPos = z;

}

Line 156 ⟶ 159:

final boolean hasTwoDigits;

if (number >= 10 && number < 100) {

hasTwoDigits = true;

}

if (number > -100 && number <= -10) {

hasTwoDigits = true; // compile-error because the final variable might already be assigned.

}

</syntaxhighlight>

Line 168 ⟶ 171:

if (number % 2 == 0) {

isEven = true;

}

Line 181 ⟶ 184:

if (number % 2 == 0) {

isEven = true;

}

Line 208 ⟶ 211:

==C# analogs for final keyword ==

[[C Sharp (programming language)|C#]] can be considered as similar to Java, in terms of its language features and basic syntax: Java has JVM, C# has .Net Framework; Java has bytecode, C# has MSIL; Java has no pointers (real memory) support, C# is the same.

Regarding the final keyword, C# has two related keywords: