Learn to use iterator for work

Iterator is called an iterator. The iterator works with containers, such as the string and vector libraries. The iterator has two tasks: positioning and value. In my understanding, it is a high-level pointer. Why use it? I think it's flexible, but it's not as error-prone as a pointer!

Let's take a look at my toy experience:

 
# Include <iostream> # include <vector> using namespace STD; int main () {vector <int> vec1; vec1.push _ back (1); vec1.push _ back (2 ); vec1.push _ back (5); For (vector <int>: iterator iter = vec1.begin (); iter! = Vec1.end (); ++ ITER) {cout <* ITER <Endl ;}}
 

Explanation: premise: as long as the vector library is used, it must be included. I first defined an integer vec1 object. Interestingly, the vector class template uses the default destructor for initialization when defining vec1. It should be empty.

Add three numbers, 1, 2, and 5 to the vec1 object. just remember the interesting command. The object name plus the dot is added with the word push and underline, and then the real parameters of the word back and function are replaced by parentheses and values.

So how can we output the values in vec1 one by one? Here we use a safer and more flexible iterator. It must be a for or while loop. First define the matching iterator ITER,

 
Vector <int>: iterator ITER
 

I didn't write two colons at the beginning.ProgramError.

If the data type is string, replace int with string.

Finally, use

* ITER

Programming is still fun, haha.