Contenido del Curso
Java Extended
Java Extended
Final Keyword
How to prevent changing the value of a variable
For this purpose, Java has a keyword called final
. Let's consider a code snippet where we use this keyword:
Main
package com.example; public class Main { public static void main(String[] args) { int number = 10; final int finalNumber = 5; number = 15; finalNumber = 20; System.out.println(number); System.out.println(finalNumber); } }
You can see that in the code above, we have created two variables of type int
, but one of them is marked with the final
keyword. When we try to change the value of this variable, the compiler tells us about an error. Specifically, it indicates that we cannot modify a value that is marked with the final
keyword.
What can we use final
keyword for:
- To create constants. A constant is a variable whose value cannot be changed after it has been initialized. In Java, constants are always declared using the
final
keyword; - To indicate that the value of a variable is final and should not be modified;
- To prevent accidental modification of a final variable's value in our code.
Note
Just using the keyword
final
alone is not enough to create a constant. To create constants, the constructprivate static final
is used. Additionally, all constants have uppercase names separated by underscores, for example:
private static final int NUMBER_OF_CHESS_PLAYERS = 2;
Tarea
Here is the code where I create multiple variables and perform mathematical operations on them. However, I only perform these operations on certain variables. Your task is to add the final
keyword before the variables that I do not modify in this code to prevent me from accidentally changing them later.
Note
It is not necessary to use
final
everywhere. Use this keyword only when you are certain that you will not need to change the value of the variable in the future. If you use this keyword where it is not needed, you may confuse yourself in your own code.
¡Gracias por tus comentarios!
Final Keyword
How to prevent changing the value of a variable
For this purpose, Java has a keyword called final
. Let's consider a code snippet where we use this keyword:
Main
package com.example; public class Main { public static void main(String[] args) { int number = 10; final int finalNumber = 5; number = 15; finalNumber = 20; System.out.println(number); System.out.println(finalNumber); } }
You can see that in the code above, we have created two variables of type int
, but one of them is marked with the final
keyword. When we try to change the value of this variable, the compiler tells us about an error. Specifically, it indicates that we cannot modify a value that is marked with the final
keyword.
What can we use final
keyword for:
- To create constants. A constant is a variable whose value cannot be changed after it has been initialized. In Java, constants are always declared using the
final
keyword; - To indicate that the value of a variable is final and should not be modified;
- To prevent accidental modification of a final variable's value in our code.
Note
Just using the keyword
final
alone is not enough to create a constant. To create constants, the constructprivate static final
is used. Additionally, all constants have uppercase names separated by underscores, for example:
private static final int NUMBER_OF_CHESS_PLAYERS = 2;
Tarea
Here is the code where I create multiple variables and perform mathematical operations on them. However, I only perform these operations on certain variables. Your task is to add the final
keyword before the variables that I do not modify in this code to prevent me from accidentally changing them later.
Note
It is not necessary to use
final
everywhere. Use this keyword only when you are certain that you will not need to change the value of the variable in the future. If you use this keyword where it is not needed, you may confuse yourself in your own code.
¡Gracias por tus comentarios!
Final Keyword
How to prevent changing the value of a variable
For this purpose, Java has a keyword called final
. Let's consider a code snippet where we use this keyword:
Main
package com.example; public class Main { public static void main(String[] args) { int number = 10; final int finalNumber = 5; number = 15; finalNumber = 20; System.out.println(number); System.out.println(finalNumber); } }
You can see that in the code above, we have created two variables of type int
, but one of them is marked with the final
keyword. When we try to change the value of this variable, the compiler tells us about an error. Specifically, it indicates that we cannot modify a value that is marked with the final
keyword.
What can we use final
keyword for:
- To create constants. A constant is a variable whose value cannot be changed after it has been initialized. In Java, constants are always declared using the
final
keyword; - To indicate that the value of a variable is final and should not be modified;
- To prevent accidental modification of a final variable's value in our code.
Note
Just using the keyword
final
alone is not enough to create a constant. To create constants, the constructprivate static final
is used. Additionally, all constants have uppercase names separated by underscores, for example:
private static final int NUMBER_OF_CHESS_PLAYERS = 2;
Tarea
Here is the code where I create multiple variables and perform mathematical operations on them. However, I only perform these operations on certain variables. Your task is to add the final
keyword before the variables that I do not modify in this code to prevent me from accidentally changing them later.
Note
It is not necessary to use
final
everywhere. Use this keyword only when you are certain that you will not need to change the value of the variable in the future. If you use this keyword where it is not needed, you may confuse yourself in your own code.
¡Gracias por tus comentarios!
How to prevent changing the value of a variable
For this purpose, Java has a keyword called final
. Let's consider a code snippet where we use this keyword:
Main
package com.example; public class Main { public static void main(String[] args) { int number = 10; final int finalNumber = 5; number = 15; finalNumber = 20; System.out.println(number); System.out.println(finalNumber); } }
You can see that in the code above, we have created two variables of type int
, but one of them is marked with the final
keyword. When we try to change the value of this variable, the compiler tells us about an error. Specifically, it indicates that we cannot modify a value that is marked with the final
keyword.
What can we use final
keyword for:
- To create constants. A constant is a variable whose value cannot be changed after it has been initialized. In Java, constants are always declared using the
final
keyword; - To indicate that the value of a variable is final and should not be modified;
- To prevent accidental modification of a final variable's value in our code.
Note
Just using the keyword
final
alone is not enough to create a constant. To create constants, the constructprivate static final
is used. Additionally, all constants have uppercase names separated by underscores, for example:
private static final int NUMBER_OF_CHESS_PLAYERS = 2;
Tarea
Here is the code where I create multiple variables and perform mathematical operations on them. However, I only perform these operations on certain variables. Your task is to add the final
keyword before the variables that I do not modify in this code to prevent me from accidentally changing them later.
Note
It is not necessary to use
final
everywhere. Use this keyword only when you are certain that you will not need to change the value of the variable in the future. If you use this keyword where it is not needed, you may confuse yourself in your own code.