[Solved] C – Is there a way to leave a variable unchanged outside of the loop?

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You may be looking for the declaration of additional blocks as in

#include<stdio.h>
int main() {
  int i=1;
  printf("before %d\n",i);
  {
    int i=0;
    printf("within %d\n",i);
  }
  printf("after %d\n",i);
  return(0);
}

which when executed yields

before 1
within 0
after 1

From the comment I grasp that a function invocation may be preferable which may be like

#include<stdio.h>
int div_10_count(long long val) {
    int count=0;
    while(val>0) {
        val /= 10;
        count++;
    }
    return(count);
}

int main() {
  long long val=10000000000L;
  printf("Before: val=%lld\n",val);
  printf("Returned: %d\n",div_10_count(val));
  printf("After: val=%lld\n",val);
  return(0);
}

shows

Before: val=10000000000
Returned: 11
After: val=10000000000

so the variable val remains unchanged even though the function works with it. This would be different when passing the parameter by reference, i.e. as indicated with the “&”.

2

solved C – Is there a way to leave a variable unchanged outside of the loop?