Dereference and Increment on vector Iterators
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The operations on iterator types let us retrieve element to which an iterator refers and let us move an iterator from one element to another.
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Iterator types use the dereference operator (the * operator) to access the element to which the iterator refers:
*iter=0; //The effect of this statement is to assign 0 to that element
- The dereference operator returns the element that the iterator currently denotes.Assuming iter refers to the first element of the vector,then *iter is the same element as ivec[0].The effect of this statement is to assign 0 to that element.
A Program that Uses Iterators
- Assume we had a vector
named ivec and we wanted to reset each of its elements to zero.We might do so by using a subscript:
for(vector<int>::size_type ix=0;ix!=ivec.size();++ix)
ivec[ix]=0; //reset all the elements in ivec to 0
- A more typical way to write this loop would use iterators:
for(vector<int>::iterator iter=ivec.begin();iter!=ivec.end();++iter
| The First | The Second |
|---|---|
| subscript | ['sab skript]下标 |
| norm | 范数 |