Java语句：混淆代码

Java语句：混淆代码 - `？：`[复制](Java statements: Obfuscated code - `?:` [duplicate])

可能重复： 什么是Java？：运算符被调用，它做了什么？

我试图阅读二叉树的实现，我遇到了这一行代码：

if (...) { ... } else { node = ( node.left != null ) ? node.left : node.right; //this line } return node;

谁能告诉我这条线的含义是什么？ 我最好的猜测是它是某种条件陈述。

Possible Duplicate: What is the Java ?: operator called and what does it do?

I am trying to read an implementation of a binary tree, and I ran across this one line of code:

if (...) { ... } else { node = ( node.left != null ) ? node.left : node.right; //this line } return node;

Can anyone tell me what this line means? My best guess is that it's a conditional statement of some kind.

最满意答案

它被称为Conditional Operator 。

在expression1 ? expression2: expression3 expression1 ? expression2: expression3 ， expression1返回一个boolean值。 如果为true则计算expression2 ，否则计算expression3 。

所以在你的代码片段中： -

node = ( node.left != null ) ? node.left : node.right;

相当于： -

if (node.left != null) { node = node.left; } else { node = node.right; }

It is called Conditional Operator.

In expression1 ? expression2: expression3, the expression1 returns a boolean value. If it is true then expression2 is evaluated, else expression3 is evaluated.

So in your code snippet: -

node = ( node.left != null ) ? node.left : node.right;

is equivalent to: -

if (node.left != null) { node = node.left; } else { node = node.right; }