java - 如何在Java中从另一个调用一个构造函数？(How do I call one constructor from another in Java?)

Question

Is it possible to call a constructor from another (within the same class, not from a subclass)?

(是否可以从另一个（在同一类中，而不是在子类中）调用构造函数？)

If yes how?

(如果是，怎么办？)

And what could be the best way to call another constructor (if there are several ways to do it)?

(调用另一个构造函数的最佳方法是什么（如果有几种方法可以做到）？)

  ask by ashokgelal translate from so

Answer 1

Yes, it is possible:

(对的，这是可能的：)

public class Foo {
    private int x;

    public Foo() {
        this(1);
    }

    public Foo(int x) {
        this.x = x;
    }
}

To chain to a particular superclass constructor instead of one in the same class, use super instead of this .

(要链接到特定的超类构造函数而不是同一类中的构造函数，请使用super代替this 。)

Note that you can only chain to one constructor , and it has to be the first statement in your constructor body .

(请注意， 您只能链接到一个构造函数 ，并且它必须是构造函数主体中的第一条语句 。)

See also this related question , which is about C# but where the same principles apply.

(另请参见与 C＃有关但适用相同原理的相关问题 。)