La palabra clave final se usa en diferentes contextos. En primer lugar, final es un modificador de no acceso aplicable solo a una variable, un método o una clase. Los siguientes son diferentes contextos donde se usa final.
Java
// Java Program to demonstrate Different
// Ways of Initializing a final Variable
// Main class
class GFG {
// a final variable
// direct initialize
final int THRESHOLD = 5;
// a blank final variable
final int CAPACITY;
// another blank final variable
final int MINIMUM;
// a final static variable PI
// direct initialize
static final double PI = 3.141592653589793;
// a blank final static variable
static final double EULERCONSTANT;
// instance initializer block for
// initializing CAPACITY
{
CAPACITY = 25;
}
// static initializer block for
// initializing EULERCONSTANT
static{
EULERCONSTANT = 2.3;
}
// constructor for initializing MINIMUM
// Note that if there are more than one
// constructor, you must initialize MINIMUM
// in them also
public GFG()
{
MINIMUM = -1;
}
}
Java
// Java Program to demonstrate
// Reference of Final Variable
// Main class
class GFG {
// Main driver method
public static void main(String[] args)
{
// Creating sn object of StringBuilder class
// Final reference variable
final StringBuilder sb = new StringBuilder("Geeks");
// Printing the element in StringBuilder object
System.out.println(sb);
// changing internal state of object reference by
// final reference variable sb
sb.append("ForGeeks");
// Again printing the element in StringBuilder
// object after appending above element in it
System.out.println(sb);
}
}
Java
// Java Program to Demonstrate Re-assigning
// Final Variable will throw Compile-time Error
// Main class
class GFG {
// Declaring and customly initializing
// static final variable
static final int CAPACITY = 4;
// Main driver method
public static void main(String args[])
{
// Re-assigning final variable
// will throw compile-time error
CAPACITY = 5;
}
}
Java
// Java program to demonstrate
// local final variable
// Main class
class GFG {
// Main driver method
public static void main(String args[])
{
// Declaring local final variable
final int i;
// Now initializing it with integer value
i = 20;
// Printing the value on console
System.out.println(i);
}
}
Java
// Java Program to demonstrate Final
// with for-each Statement
// Main class
class GFG {
// Main driver method
public static void main(String[] args)
{
// Declaring and initializing
// custom integer array
int arr[] = { 1, 2, 3 };
// final with for-each statement
// legal statement
for (final int i : arr)
System.out.print(i + " ");
}
}
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Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA