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Convert double value to char array in C

How to convert double value to char array in C?

double a=2.132;
char arr[8];

Is there a way to do this in standard C? Can anyone give any solution?

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6 answers

If you are going to store a double DATA, not a readable representation, then:

#include <string.h>

double a=2.132;
char arr[sizeof(a)];
memcpy(arr,&a,sizeof(a));
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To create a character string representing a number in human-readable form, use snprintf (), as in the code below.

To access double bytes, use concatenation. For example, the union u {double d; char arr [8]; }

, , , . . atof() . 4 :

u.d = 2.132000     u.arr =  75 ffffff93 18 04 56 0e 01 40
res = 2.13200000
u.d = 37.456700     u.arr =  ffffffa6 0a 46 25 75 ffffffba 42 40
res = 37.45670000

:

#include <stdio.h>
#include <stdlib.h>
union MyUnion { char arr[8];  double d; };

void printUnion (union MyUnion u) {
  int i;
  enum { LEN=40 };
  char res[LEN];
  printf ("u.d = %f     u.arr = ", u.d);
  for (i=0; i<8; ++i)
    printf (" %02x", u.arr[i]);
  printf ("\n");
  snprintf (res, LEN, "%4.8f", u.d);
  printf ("res = %s\n", res);
}
int main(void) {
  union MyUnion mu = { .d=2.132 };
  printUnion (mu);
  mu.d = atof ("37.4567");
  printUnion (mu);
  return 0;
}
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- , sprintf:

:

char charray[200];
double num = 11.1111111111111;

sprintf(charray, "%2.13f", num);
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, , , :

double a=2.132;
double darr[1] = { a };
char *arr = (char*) darr;

, , char, char

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, , - snprintf, :

snprintf(arr, 8, "%2.4f", a);

: http://msdn.microsoft.com/en-us/library/2ts7cx93(VS.71).aspx

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double b = 222.215;

        String bb=""+b;

        char[] tab=new char[bb.length()];

        for(int m=0;m<bb.length();m++)
        {
            tab[i]=bb.charAt(m);
        }//un tableau mtn qui contient notre resultat dans un tableua de char
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