Android在ArrayList中查找重复值[重复]

Question

有一个这样的 ArrayList。想知道重复了多少个值： 示例：人：4 次，女孩：4 次

public ArrayList<String> new_contains_all= new ArrayList<>();

...

[[laying, beautiful, brushing, group, young, head, bed, close, couple, female, teeth, white, indoor, pair, holding, sunglasses, stuffed, wearing, posing, dress, person, hair, standing, looking, girl, red, playing, made, top, woman, lady, hat, clothing, goggles, people],
     [person, hair, young, shirt, looking, phone, girl, white, glasses, food, sunglasses, wearing, woman, hat], [blue, beautiful, person, cake, standing, young, shirt, black, female, board, girl, white, photo, holding, ready, wearing, top, posing, woman, lady, smiling, clothing, dress, suitcase], [street, clock, light, stop, sign, red, text, sitting,
     man, photo, traffic], [blue, person, young, looking, phone, sitting, female, girl, photo, computer, using, red, laptop, holding, glasses, food, sunglasses, wearing, top, woman, lady, hat]]

通知 Array 里面有 5 个元素。

已经尝试过了，这应该适用于简单的 ArrayList，但每个元素有超过 1 个字符串，这令人毛骨悚然，我知道解决方案必须在键内实现另一个 bucle，但今天太累了：/ 也许有人让我眨眼：P

List<String> l = new_contains_all;
Set<String> s = new HashSet<String>(l);
for (String key : s) {
    int count = Collections.frequency(l, key);
    if (count > 1)
        System.out.println("Found '" + key + "' " + count + " times."+"key: "+key.toString()+"l: "+l.toString());
}

Answer 1

您几乎解决了您的问题，但您的代码中有一个细微的错误：

Set<String> s = new HashSet<String>(l);

Set 的核心属性是：它不允许重复。因此，这一次调用只是从输入列表 l 中删除所有重复项。

因此：所有频率都是一个。

因此，您可以这样做：

for (String singleWord: new_contains_all) {
  count = Collections.frequency(new_contains_all, singleWord);
...