How do I assign cumbersome repetitive values to an array?

Question

I want to create an array of 10 × 10, which contains '.' for each element. So I write as :

int A[10][10]={ '.','.','.','.',

(wait a minute I have to write 100 full stops and 100 commas)

               '.','.','.'}

Another method is to write '.', 10 times and then copy paste it 10 times, but still this takes time and I don't think this is the smartest method.

Is there a smarter method? I don't want to write so long full stops.

@unwind The "c++ lounge" is [Lounge](http://chat.stackoverflow.com/rooms/10/loungec) (_in response to now-deleted [comment thread](http://stackoverflow.com/questions/30756630/how-do-i-assign-cumbersome-repetitive-values-to-an-array/30756668#comment49566536_30756668)_) — sehe, Jun 10 '15 at 13:08

Lundin · Accepted Answer · 2015-06-10T13:12:38.913

9

The only feasible way to initialize an array like this, is (unfortunately) by using a flood of macros:

#define ONE_DOT '.',
#define TWO_DOTS ONE_DOT ONE_DOT
#define FIVE_DOTS TWO_DOTS TWO_DOTS ONE_DOT
#define TEN_DOTS { FIVE_DOTS FIVE_DOTS },
#define TWENTY_DOTS TEN_DOTS TEN_DOTS
#define FIFTY_DOTS TWENTY_DOTS TWENTY_DOTS TEN_DOTS
#define ONE_HUNDRED_DOTS FIFTY_DOTS FIFTY_DOTS


int A[10][10] = { ONE_HUNDRED_DOTS };

edited Jun 10 '15 at 13:12

answered Jun 10 '15 at 13:00

Lundin

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5

It almost looks like song lyrics. – Quentin Jun 10 '15 at 13:02
1

@Quentin Feel free to use the code as lyrics for your next mainstream pop hit :) – Lundin Jun 10 '15 at 13:04
@Lundin Thank you very much! – The Artist Jun 10 '15 at 13:13

score 1 · Answer 2 · answered Jun 10 '15 at 12:42

1

Use a for loop statement to assign all elements to '.' ----

char A[10][10];
int i,j;
for(i=0;i<10;i++)
  for(j=0;j<10;j++)
     A[i][j]='.';

answered Jun 10 '15 at 12:42

Sourav Kanta

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This isn't initialization, however. For example, what if A would be `const`? – Lundin Jun 10 '15 at 13:02

Sagar Kar · Answer 3 · 2015-06-10T13:05:01.440

1

Loops are the thing You want to read about now.

The simple for loop will do that for you.

char A[10][10];
int i,j;
for ( i=0;i <10;++i){
     for ( j=0;j <10;++j)
            A[i][j]='.';
 }

For further justification google loops in c/c++

edited Jun 10 '15 at 13:05

answered Jun 10 '15 at 12:46

Sagar Kar

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So, for each i between 0 and -1... well that's off to a good start. – Quentin Jun 10 '15 at 12:48
@Quentin i is intiger type, what do u mean by between 0 and -1?? – Sagar Kar Jun 10 '15 at 12:54
1

Your `for` loops go from 0 included to 0 excluded, i.e [0, 0). They won't ever be entered. – Quentin Jun 10 '15 at 12:56
Thats was a typo for 10 .... i honestly overlooked it.... Anyway i dont mind downvote to my answer but help me improve! Thanks – Sagar Kar Jun 10 '15 at 12:57
This isn't initialization, however. For example, what if A would be `const`? – Lundin Jun 10 '15 at 13:02

How do I assign cumbersome repetitive values to an array?

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