How to delete contents of matrix only if it has 2 elements?

If p = [55;56], and I want to set it to one value (ex. p = 55), how can I write an "if" statement that does this using elements? As of now, I can only do it with this specific condition, but I would like to write "if p has more than one element, then set p equal to the first element." Code:

if p == [55;56]
  p(2) =[]
end

Answer 1

[Matt J]

No need for an if-statement. Just do,

p(2:end)=[];

or

p=p(1);

[Asher Zaidi]

Perfect, thank you!