Java中的 AbstractSequentialList contains() 方法和示例
Java AbstractSequentialList的contains()方法用于检查集合中是否存在元素。它将元素作为参数,如果元素存在于集合中,则返回 True。
句法:
public boolean contains(Object element)
参数:参数元素是集合类型。该参数指的是集合中需要检查其出现的元素。
返回值:该方法返回一个布尔值。如果元素存在于集合中,则返回 True,否则返回 False。
下面的程序说明了 AbstractSequentialList.contains() 方法:
方案一:
// Java code to illustrate
// AbstractSequentialList.contains()
import java.util.*;
public class GFG {
public static void main(String args[])
{
// Creating an empty Collection
AbstractSequentialList
abs = new LinkedList();
// Use add() method to add
// elements in the collection
abs.add("Geeks");
abs.add("for");
abs.add("Geeks");
abs.add("10");
abs.add("20");
// Displaying the collection
System.out.println("AbstractSequentialList: "
+ abs);
// Check if the collection contains "Hello"
System.out.println("\nDoes the Collection"
+ " contains 'Hello': "
+ abs.contains("Hello"));
// Check if the Collection contains "20"
System.out.println("Does the collection"
+ " contains '20': "
+ abs.contains("20"));
// Check if the Collection contains "Geeks"
System.out.println("Does the Collection"
+ " contains 'Geeks': "
+ abs.contains("Geeks"));
}
}
输出:
AbstractSequentialList: [Geeks, for, Geeks, 10, 20]
Does the Collection contains 'Hello': false
Does the collection contains '20': true
Does the Collection contains 'Geeks': true
方案二:
// Java code to illustrate
// AbstractSequentialList.contains()
import java.util.*;
public class GFG {
public static void main(String args[])
{
// Creating an empty Collection
AbstractSequentialList
abs = new LinkedList();
// Use add() method to add
// elements in the collection
abs.add(10);
abs.add(20);
abs.add(30);
abs.add(40);
abs.add(50);
// Displaying the collection
System.out.println("AbstractSequentialList:"
+ abs);
// Check if the collection contains 10
System.out.println("\nDoes the Collection "
+ "contains '10': "
+ abs.contains(10));
// Check if the collection contains 50
System.out.println("\nDoes the Collection"
+ " contains '50': "
+ abs.contains(50));
// Check if the Collection contains 100
System.out.println("Does the collection"
+ " contains '100': "
+ abs.contains(100));
}
}
输出:
AbstractSequentialList:[10, 20, 30, 40, 50]
Does the Collection contains '10': true
Does the Collection contains '50': true
Does the collection contains '100': false