Alocating memory depending of a variable value INT variable

[Ali Çehreli]

On 11/19/2013 03:16 PM, Carlos wrote:> Well in C I just declared an 
array during execution with an array with a
 > multiplied variable for the size of the array.
 >
 > Since I only need two spaces in the array for each line of process it
 > was multiplied by two.
 >
 > so it was like this :
 >
 > scanf("%d", &Num);
 > int array[Num*2];

That is a VLA.

In D, you would normally use a slice. Below, 'a' and 'b' are two ways of 
having a slice with valid elements. On the other hand, 'c' is merely 
reserving space for that many elements:

import std.stdio;

void main()
{
     size_t num;
     write("How many? ");
     readf(" %s", &num);

     auto a = new int[num * 2];

     int[] b;
     b.length = num * 2;

     int[] c;
     c.reserve(num * 2);
}

Ali