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法律研究检查 Java 中元素的频率，带有 Collections.frequency
在 Java 中创建列表 -
List< String >list = Arrays.asList("P","Q","R","P","T","P","U","V","W","X","W" );现在，假设你要获得元素 P 的频率。为此，使用 Collections.frequency() 方法 -
Collections.frequency(list, "P");
如上所示，我们还可以找到任何字母的出现次数 -
Collections.frequency(list, "T");
范例
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class Demo {
public static void main(String[] args) {
List<String>list = Arrays.asList("P","Q","R","P","T","P","U","V","W","X","W" );
int checkOccurrence = Collections.frequency(list, "P");
System.out.println("Occurrence of P = " + checkOccurrence);
checkOccurrence = Collections.frequency(list, "W");
System.out.println("Occurrence of W = " + checkOccurrence);
checkOccurrence = Collections.frequency(list, "T");
System.out.println("Occurrence of T = " + checkOccurrence);
}
}输出
Occurrence of P = 3 Occurrence of W = 2 Occurrence of T = 1
更新于： 30-Jul-2019
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