How to specify the highest indexed array component?

Question

Suppose that the following in stan file.

transformed parameters {

  real <lower=0,upper=1>p[C];

}

where C is a positive integer specified by the data block.

Then by p[1] we can extract the first component. p[C] also extract the C-th componet ? Or p[C] is indicate the set of p[1],p[2],....p[C] ?

For example, Which does the code p[C] = 1 means ?

1)ONLY the C-th component of p is one

or

2)ALL components of p (i.e., p[1],p[2],....p[C] ) is one.

Answer 1

In your example,

transformed parameters {
  real<lower = 0, upper = 1> p[C]; // multivalued
  p[C] = 1; // scalar
}

The first C-1 elements of p are undefined, which is probably not good, although it is valid syntax.

Alternatively,

transformed parameters {
  real<lower = 0, upper = 1> p[C] = rep_array(1, C);
}

defines all the elements of p to be 1.