Why is dynamic array length required here?

[Ali Çehreli]

On 10/18/2018 07:04 PM, Samir wrote:

 >      myArray.length = noValues; // I get a run-time error if I comment
 > this out

It's because the expression that reads the elements below is readf, 
which reads on top of an existing element.

 >      while (i < noValues) {
 >          write("enter value #", i+1, " ");
 >          readf(" %s", &myArray[i]);

Aside: It may be possible to read like the following without taking the 
address, as readf has been improved to take references since that code 
was written:

          readf(" %s", myArray[i]);  // (not tested)

So, the answer to your question is, we need to set the length of the 
array so that there are elements to read on top of. If D had function 
templates like getResponse() that I use in the Templates chapter,

   http://ddili.org/ders/d.en/templates.html

then the best thing to do would be to append the elements directly to 
the array:

     // No need to set .length beforehand
     myArray ~= getResponse!int(/* ... */);

Ali