C++ Arrays

C++ Arrays

Arrays are used to store multiple values in a single variable, instead of declaring separate variables for each value.

To declare an array, define the variable type, specify the name of the array followed by square brackets and specify the number of elements it should store:

We have now declared a variable that holds an array of four strings. To insert values to it, we can use an array literal - place the values in a comma-separated list, inside curly braces:

To create an array of three integers, you could write:

Access the Elements of an Array

You access an array element by referring to the index number.

This statement accesses the value of the first element in cars:

Example

Change an Array Element

To change the value of a specific element, refer to the index number:

Example

Example

 

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Loop Through An Array

You can loop through the array elements with the for loop.

The following example outputs all elements in the cars array:

Example

The following example outputs the index of each element together with its value:

Example

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C++ Omit Array Size

You don't have to specify the size of the array. But if you don't, it will only be as big as the elements that are inserted into it:

This is completely fine. However, the problem arise if you want extra space for future elements. Then you have to overwrite the existing values:

If you specify the size however, the array will reserve the extra space:

Now you can add a fourth and fifth element without overwriting the others:

Omit Elements on Declaration

It is also possible to declare an array without specifying the elements on declaration, and add them later:

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