The contains () method in Java

Import java.util.arraylist;import java.util.collection;/* * boolean contains (Object  o); Determines whether an element is contained in the collection.  * boolean remove (Object o); Deletes an element from the collection collection  *///contains method The underlying invocation of the book Equals method, All elements stored in the collection should override the Equals () method. Public class colletciontest02 {public static void main (String[] args) { Collection c = new arraylist (); C.add (New integer (1)); System.out.println (C.contains (1));//Add Customercustomer cus1 = new customer ("Zhangsan", 14); Customer cus2 = new customer ("Zhangsan"); C.add (CUS1); System.out.println (C.contains (CUS2));}} public class customer {private string name;private int age;public  String getname ()  {return name;} Public void setname (String name)  {this.name = name;} Public int getage ()  {return age;} Public void setage (int age)  {this. Age = age;} Public customer (String name, int age)  {super (); this.name = name;this.age  = age;} Public customer () {}public string tostring () {return  "name="  + name + " " + "age=" + age;} Overridden the Equal method Public boolean equals (Object o) {if (this==o) {return true;} Else{if (O instanceof customer) {customer co =  (Customer) o;if (Co.name.equals (this.name) &&co.age==this.age) {return true;}}} Return false;}}

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The contains () method in Java