java - == vs equals vs XOR benchmark -

i doing benchmark find out of ==,equals , ^ (xor) potentially faster while comparing objects. purpose wrote program, , got following results:

first iteration:

equals  took : 345 ==  took : 625 xor  took : 284   

second iteration:

equals  took : 346 ==  took : 182 xor  took : 254   

total after 100 iterations:

average equals:  305 average ==:  164 average xor:  246 

i have couple of questions here:

1. using equals method faster using hashcode() first time using hashcode becomes faster after second iteration. safe if i'm using same dataset on time calculation faster use hashcode() rather equals()?
2. after checking string.hashcode() implementation know why hashcode() becomes faster second time, why xor gets faster? can't see logic that.

here program refrence:

public static void main(string... args) throws exception{      string[] set1=new string[10000000];     string[] set2=new string[10000000];     random r=new random();     for(int i=0;i<10000000;i++){         int next=r.nextint(1000);         set1[i]=next+"";         set2[i]=next+"";     }       for(int q=0;q<2;q++){  // change 2 number more iterations         long start0=system.currenttimemillis();         int equals0=0;         for(int i=0;i<1;i++){             for(int j=set2.length-1;j>=0;j--){                 if(set1[i].equals(set2[j])){                     equals0++;                 }             }         }         system.out.println("equals  took : " + (system.currenttimemillis()-start0));           long start1=system.currenttimemillis();         int equals1=0;         for(int i=0;i<1;i++){             for(int j=set2.length-1;j>=0;j--){                 if(set1[i].hashcode()==set2[j].hashcode()){                     equals1++;                 }             }         }         system.out.println("==  took : " + (system.currenttimemillis()-start1));            int equals2=0;         long start2=system.currenttimemillis();         for(int i=0;i<1;i++){             for(int j=set2.length-1;j>=0;j--){                 if((set1[i].hashcode() ^ set2[j].hashcode())==0){                     equals2++;                 }             }         }         system.out.println("xor  took : " + (system.currenttimemillis()-start2));      } 

edit: after running program running 100 iterations, realized last iteration speed using xor . still , i'm not quite sure what's special last iteration?

since way compare objects equality use equals() question moot, alternative may applicable depending on circumstances , use-case identity comparison (==).

but identity comparison , equality not same concept, need decide 1 right tool use case.