just want to ask what the differences are between variables declarations/definitions inside or outside of a loop/if/switch-case etc. for example:

int a, b, c;
unsigned i;
for( i=0; i<100; i++ )
{
  a = ...;
  b = ...;
  c = ...;
}

and

for( unsigned i=0; i<100; i++)
{
  int a = ...;
  int b = ...;
  int c = ...;
}

I am guessing there are no differences between those two; the compiler will create the same code for both?

I am asking because the latter approach (declaring/defining variables inside loop/if/switch etc.) may look clearer and reduce the number of variable declarations/definitions at the beginning of the function. ( assuming there are a significant number of variables (>10) used in a function, declaring them all at the beginning may look very messy.

could you please give some suggestions and what is the best way in practice?