How can i convert negative number to positive number ?

How can i make in such a way that the negative is ignored before adding up the number ??

Eg: I want the following the code to print out 13 instead of -1.

Code:

---

 
double hello[]={-1,2,4,-6};

for(i=0; i<=3; i++)
{
    xxx = xxx + hello[i];
}

printf("%f",xxx);

---

Code:

---

double hello[]={-1,2,4,-6};

for(i=0; i<=3; i++)
{
    if(hello[i] < 0)
        xxx -= hello[i];        /*  ex: x = x - (-1) */
    else
        xxx += hello[i];      /* ex: x = x + 2 */
}

printf("%f",xxx);

---

You can use fabs from <math.h>.

Code:

---

#include <stdio.h>
#include <math.h>

int main(void)
{
  double hello[]={-1,2,4,-6};
  double xxx = 0;
  int i;

  for(i=0; i<=3; i++)
  {
    xxx = xxx + fabs(hello[i]);
  }

  printf("%f",xxx);

  return 0;
}

---

Also note that your loop is not idiomatic. Most readers will see any deviation from the customary "for (i = 0; i < n; i++)" as a probable error. Your loop is correct, but would be better as "for (i=0; i<4; i++)".