Formulas for Lists

When you have a list, you can apply some formulas that are specific to working with lists. Here are some:

len()

You can know the number of elements a list has by using the len operator.

Syntax: len( List )

cat()

Also, you can join two lists (as long as they have the same type) by using the cat formula:

(cat is an abbreviation of concatenate).

Syntax: cat( List, List )

Alternative Syntax: cat( Item, List )

You can also use this formula to push an element to the end of a list, resulting in a new list:

In Decipad, every operation returns a new value. Here, cat returns a new list and leaves the arguments untouched.

Or add an element to the beginning of a list:

first()

If you have a list and want to extract the first element, you can use the first formula:

Syntax: first( List )

last()

Conversely, if you want to extract the last element of a list, you can use the last formula:

Syntax: last( List )

sort()

You can generate a new list that contains all the elements in the source list sorted:

Syntax: sort( List )

unique()

You can generate a new list that contains all the unique elements in the source list sorted:

Syntax: unique( List )

reverse()

You can generate a new list that contains all the elements in the source list in reverse order:

Syntax: reverse( List )