Generics are a facility of generic programming that were added to the Java programming language in 2004 within version J2SE 5.0.
Generics allows parameterized type to use with method, class and interface.
This example code shows how to create and use Generic Constructor in Java.
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class GenericConstructor { private double value; <T extends Number> GenericConstructor(T arg) { value = arg.doubleValue(); } void showValue() { System.out.println("value: " + value); } } public class GenericConstructorTest { public static void main(String args[]) { GenericConstructor gc1 = new GenericConstructor(100); GenericConstructor gc2 = new GenericConstructor(123.5F); gc1.showValue(); gc2.showValue(); } } |
Output:
value: 100.0
value: 123.5
value: 123.5