Skip to Content
Learn
Vectors
Initializing a Vector

Now we know how to create a vector, we can also initialize a vector, giving it values, as we are creating it in the same line.

For example, instead of just creating a double vector named location:

std::vector<double> location;

We can create and initialize location with specific values:

std::vector<double> location = {42.651443, -73.749302};

Here, we are storing a latitude and a longitude.

So it would look something like this:

Vector

Another way we can initialize our vector is by presizing, or setting the size.

Suppose we want to create and initialize a vector with two elements. However, we don’t know what values we want to add yet:

std::vector<double> location(2);

Here, we are creating a double vector and setting the initial size to two using parentheses.

It would look something like this:

presize

Because 0.0 is the default value for double.

Instructions

1.

Suppose the Tokyo Subway costs are as follows:

Ticket Adult Child
24-hour ¥800 ¥400
48-hour ¥1200 ¥600
72-hour ¥1500 ¥750

We have initialized the subway_adult already for you.

Initialize the subway_child vector with:

  • 400
  • 600
  • 750

Note: The vector can still be double even though the values entered are ints.

Folder Icon

Take this course for free

Already have an account?