# Java `ArrayList contains()`方法 > 原文： [https://beginnersbook.com/2013/12/java-arraylist-contains-method-example/](https://beginnersbook.com/2013/12/java-arraylist-contains-method-example/) `ArrayList contains()`方法用于檢查給定列表中指定的元素是否存在。 `public boolean contains(Object element)` 如果在列表中找到指定的元素，則返回`true`，否則返回`false`。 ### 例 在這個例子中，我們有兩個`ArrayList`（`ArrayList<String>`和`ArrayList<Integer>`），我們正在檢查兩個列表中是否存在少量元素。 ```java package beginnersbook.com; import java.util.ArrayList; public class ContainsExample { public static void main(String[] args) { ArrayList<String> al = new ArrayList<String>(); al.add("pen"); al.add("pencil"); al.add("ink"); al.add("notebook"); System.out.println("ArrayList contains the string 'ink pen': " +al.contains("ink pen")); System.out.println("ArrayList contains the string 'pen': " +al.contains("pen")); System.out.println("ArrayList contains the string 'pencil': " +al.contains("pencil")); System.out.println("ArrayList contains the string 'book': " +al.contains("book")); ArrayList<Integer> al2 = new ArrayList<Integer>(); al2.add(1); al2.add(99); al2.add(56); al2.add(13); al2.add(44); al2.add(6); System.out.println("'1' is present in arraylist: "+al2.contains(1)); System.out.println("'55' is present in arraylist: "+al2.contains(55)); System.out.println("'44' is there in arraylist: "+al2.contains(44)); System.out.println("'7' is there in arraylist: "+al2.contains(7)); } } ``` 輸出： ```java ArrayList contains the string 'ink pen': false ArrayList contains the string 'pen': true ArrayList contains the string 'pencil': true ArrayList contains the string 'book': false '1' is present in arraylist: true '55' is present in arraylist: false '44' is there in arraylist: true '7' is there in arraylist: false ``` #### 參考： [`ArrayList.contains(Object)`](https://docs.oracle.com/javase/6/docs/api/java/util/ArrayList.html#contains(java.lang.Object))