The Hasnext method and next method of Iterator

Both methods have a pointer to the move, and the difference is that one returns a Boolean and a return object:

Hasnext (): Determines whether the current element exists and does not point to the move

Next (): Returns the current element and refers to the next element

Take a look at the code:

linkedhashmap<string, string> myMap = new linkedhashmap<string, string> ();

MyMap. Put ("0", "0.0");

MyMap. Put ("1", "1.0");

MyMap. Put ("2", "2.0");

Set<string> MySet = Mymap.keyset ();

int i=0,j=0;

for (iterator<string> Iterator = Myset.iterator (); Iterator.hasnext ();) {// last i=3

Iterator.hasnext ();//The execution of this method here does not affect the overall traversal

i++;

String Theone=iterator.next ();

System.out.println (i+ "--" +theone);

}

for (iterator<string> Iterator = Myset.iterator (); Iterator.hasnext ();) {// last j=2

j + +;

String Theone=iterator.next ();

System.out.println (j+ "--" +theone);

Iterator.next ();//The execution of this method here affects the execution of the overall traversal

}

The Hasnext method and next method of Iterator