ハーシュコードの集合紹介

package comp.itheime.demo 03.hashCode;/*

   :         ,       (        ,       ,         ,             )
 Object      ,          
int hashCode()           。
hashCode     :
    public native int hashCode();
    native:                  

*/public class Demo 01HashCode｛

public static void main(String[] args) {
    //Person    Object ,      Object  hashCode  
    Person p1 = new Person();
    int h1 = p1.hashCode();
    System.out.println(h1);//1967205423  | 1

    Person p2 = new Person();
    int h2 = p2.hashCode();
    System.out.println(h2);//42121758   |  1

    /*
        toString     :
            return getClass().getName() + "@" + Integer.toHexString(hashCode());
     */
    System.out.println(p1);//com.itheima.demo03.hashCode.Person@75412c2f
    System.out.println(p2);//com.itheima.demo03.hashCode.Person@282ba1e
    System.out.println(p1==p2);//false

    /*
        String     
            String   Obejct  hashCode  
     */
    String s1 = new String("abc");
    String s2 = new String("abc");
    System.out.println(s1.hashCode());//96354
    System.out.println(s2.hashCode());//96354

    System.out.println("  ".hashCode());//1179395
    System.out.println("  ".hashCode());//1179395
}

)package comp.itheim.demo 03.hashCode;
public class Person extens Object｛

//  hashCode  

@Override
public int hashCode() {
    return  1;
}

)