Java 如何计算将谓词与 Streams 匹配的元素数量？
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时间：2020-08-11 14:22:48 来源:igfitidea点击:
How can I count the number of elements that match a predicate with Streams?
提问by ImTomRS
In Java7 I have this code:
在 Java7 我有这个代码：
public int getPlayersOnline() {
int count = 0;
for (Player player : players) {
if (player.isActive()) {
count++;
}
}
return count;
}
I'm trying to use Java 8 features as much as possible, how can I go about improving this with lambdas?
我正在尝试尽可能多地使用 Java 8 功能，我该如何使用 lambda 来改进它？
采纳答案by Louis Wasserman
This would be a one-liner:
这将是一个单行：
return (int) players.stream().filter(Player::isActive).count();
