Multiple conditions in a C 'for' loop

Question

I came across this piece of code. I generally use \'&&\' or \'||\' to separate multiple conditions in a for loop, but this code uses commas to do that.<

Answer 1

Of course it is right what you say at the beginning, and C logical operator && and || are what you usually use to "connect" conditions (expressions that can be evaluated as true or false); the comma operator is not a logical operator and its use in that example makes no sense, as explained by other users. You can use it e.g. to "concatenate" statements in the for itself: you can initialize and update j altogether with i; or use the comma operator in other ways

#include 

int main(void)  // as std wants
{
  int i, j;

  // init both i and j; condition, we suppose && is the "original"
  // intention; update i and j
  for(i=0, j=2; j>=0 && i<=5; i++, j--)
  {
       printf("%d ", i+j);
  }
  return 0;        
}