java什么算被调用_什么是Java？：运算符被调用,它做什么？

是的&＃xff0c;它是一种速记形式

int count;

if (isHere)

count &＃61; getHereCount(index);

else

count &＃61; getAwayCount(index);

它被称为条件运算符。许多人(错误地)称之为三元运算符&＃xff0c;因为它是Java&＃xff0c;C&＃xff0c;C和可能许多其他语言中唯一的三元(三参数)运算符。但是理论上可以有另一个三元运算符&＃xff0c;而只能有一个条件运算符。

§15.25 Conditional Operator ? :

The conditional operator ? : uses the boolean value of one expression to decide which of two other expressions should be evaluated.

请注意&＃xff0c;两个分支都必须使用带有返回值的方法&＃xff1a;

It is a compile-time error for either the second or the third operand expression to be an invocation of a void method.

In fact, by the grammar of expression statements (07001), it is not permitted for a conditional expression to appear in any context where an invocation of a void method could appear.

所以&＃xff0c;如果doSomething()和doSomethingElse()是void方法&＃xff0c;你不能压缩这&＃xff1a;

if (someBool)

doSomething();

else

doSomethingElse();

进入&＃xff1a;

someBool ? doSomething() : doSomethingElse();

简单词&＃xff1a;

booleanCondition ? executeThisPartIfBooleanConditionIsTrue : executeThisPartIfBooleanConditionIsFalse