Explain telescopic constructor pattern in Java.

In Java there is no support for default values for constructor parameters.

Telescoping constructor comes to the rescue. A class has multiple constructors, where each constructor calls a more specific constructor in the hierarchy, which has more parameters than itself, providing a default value for the extra parameters. The next constructor does the same until there is no left.

public Person(String firstName, String lastName) {
        this(firstName, lastName, null);
    }
 
    public Person(String firstName, String lastName, String description) {
        this(firstName, lastName, description, 0);
    }
 
    public Person(String firstName, String lastName, String description, int age) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.description = description;
        this.age = age;
    }

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