For Loops in C++

A for loop is a special type of loop in C++ which allows us to loop over the items of a collection, such as a string or a vector.

Looping through a string:

For example, a string is a sequence of characters, so we can use a for loop to iterate over each character and do something with that character:

string name = "Andy";

for(char letter : name) {
  cout << letter << endl;
}

Let's break down this code:

• The for keyword that indicates the start of a for loop.
• char letter is the loop variable. It will take the value of each different item in the collection
• The : separates the loop variable from the collection we will iterate on
• name is the collection to loop over

The output of this code is:

A
n
d
y

As you can see, on each iteration, letter was assigned the value of the next item in the string and inside the loop, we printed that value.

Looping through a vector:

We can also use for loops with lists:

vector<string> fruits = {"banana", "orange", "pear", "kivi"};

for (string fruit : fruits) {
  cout << "I eat " + fruit << endl;
}

The output of this code is:

I eat banana
I eat orange
I eat pear
I eat kivi

Assignment
Now let's greet our friends using a for loop!

Hint
Look at the examples above if you get stuck.