Chapter 7: Lists

So far, we have explored the string and number type. These are great for exactly that, text and numerical values. What if we want to store a collection of strings and numbers? Meet your companion, the list.

obj x = [];

The list type is a static collection that can be grown, shrunk, indexed, combined, and more. It can store any type separated by commas:

obj x = ["Object in the list", 1, 2, 3, 4];

To access a value in a list, we can index it:

obj x = [1, 2, 3, 4];

# 'retrieve' will get the value at index 'i'

obj value_in_list = retrieve(x, 0); # in this case, index 0 is the first item in the list

To add a value to a list, we can push it:

obj x = [];

# 'push' will return a new list with the added value

obj x = push(x, "value");

To get rid of a value in a list, we can remove it:

obj x = [1, 2, 3, 4, 5];

# 'remove' will return a new list with the removed index

obj x = remove(x, 4); # list looks like: [1, 2, 3, 4]

To combine two lists, we can append them:

obj x = [1, 2];

obj y = [3, 4];

# 'append' will return the two lists combined with each other

obj combined = append(x, y);

And lastly, we can reverse the values in a list:

obj x = [3, 2, 1];

# 'reverse' will return a new list with reversed values

obj reversed = reverse(x);

With all these operations, you may have noticed we return a new list. This is because the list type is static, meaning we can't modify it in place; we have to create a new list for every modification. 

In programming, this is referred to as "immutable" data. Why GLang does this