• steven kladitis (15/15) Mar 21 2018 import std.stdio;
• Adam D. Ruppe (4/6) Mar 21 2018 array3 is empty. You are trying to set a value that doesn't
• steven kladitis (22/28) Mar 22 2018 import std.stdio;
• Nicholas Wilson (18/19) Mar 22 2018 int[] x; is like

steven kladitis <stevenkladitis gmail.com> writes:

import std.stdio;

void main(){
int[3] array1 = [ 10, 20, 30 ];
auto array2 = array1; // array2's elements are different
// from array1's
array2[0] = 11;
int[] array3;
//array4[0]=3;
array3[0]=4;
auto array4 = array3;

writeln(array1,'\n',array2,'\n',array3,'\n',array4);
}


-- windows 7 64 bit ( os ) dmd 2.079.0
-- thanks
-- Steven

Adam D. Ruppe <destructionator gmail.com> writes:

On Wednesday, 21 March 2018 at 18:53:39 UTC, steven kladitis 
wrote:
 int[] array3;
 array3[0]=4;

array3 is empty. You are trying to set a value that doesn't 
exist..

steven kladitis <stevenkladitis gmail.com> writes:

On Wednesday, 21 March 2018 at 18:55:34 UTC, Adam D. Ruppe wrote:
 On Wednesday, 21 March 2018 at 18:53:39 UTC, steven kladitis 
 wrote:
 int[] array3;
 array3[0]=4;

 array3 is empty. You are trying to set a value that doesn't 
 exist..

import std.stdio;

void main(){
int[3] array1 = [ 10, 20, 30 ];
auto array2 = array1; // array2's elements are different
// from array1's
array2[0] = 11;
int[] array3;
//array4[0]=3;
array3 ~=4;
auto array4 = array3;
array4 ~=2;
int[string] a1;
int[int] a2;

a1["V"]=2;
a2[4]=3;

writeln(array1,'\n',array2,'\n',array3,'\n',array4,'\n',a1,'\n',a2);
}

-- this works, why??
-- what is the difference between int[] x; and int[int] x; ????
-- thanks
-- Steven

Nicholas Wilson <iamthewilsonator hotmail.com> writes:

On Thursday, 22 March 2018 at 14:05:02 UTC, steven kladitis wrote:
 -- what is the difference between int[] x; and int[int] x; ????

int[] x; is like
struct _Int_Array
{
     size_t len;
     int* ptr;
}
_Int_Array y;
int i = 5;
x[i] = i; // this and the line below crash or assert, due to a 
null pointer
*(y.ptr +i) = 5;
are both the same;

int[int] is a completely different beast. is it a hashtable that 
maps ints to int.
its a lot closer to int[string] than it is to int[]

see https://dlang.org/spec/arrays.html vs 
https://dlang.org/spec/hash-map.html