Output of C Programs | Set 13

Difficulty Level: Rookie

Question 1
Predict the output of below program.

int main()
{
  char arr[] = "geeksforgeeks";
  printf("%d", sizeof(arr));
  getchar();
  return 0;
}

Output: 14
The string “geeksforgeeks” has 13 characters, but the size is 14 because compiler includes a single ‘\0’ (string terminator) when char array size is not explicitly mentioned.

Question 2
In below program, what would you put in place of “?” to print “geeks”. Obviously, something other than “geeks”.

int main()
{
  char arr[] = "geeksforgeeks";
  printf("%s", ?);
  getchar();
  return 0;
}

Answer: (arr+8)
The printf statement prints everything starting from arr+8 until it finds ‘\0’

Question 3
Predict the output of below program.

int main()
{
  int x, y = 5, z = 5;
  x = y==z;
  printf("%d", x);

  getchar();
  return 0;
}

The crux of the question lies in the statement x = y==z. The operator == is executed before = because precedence of comparison operators (<=, >= and ==) is higher than assignment operator =.
The result of a comparison operator is either 0 or 1 based on the comparison result. Since y is equal to z, value of the expression y == z becomes 1 and the value is assigned to x via the assignment operator.

Question 4
Predict the output of below program.

int main()
{
  printf(" \"GEEKS %% FOR %% GEEKS\"");
  getchar();
  return 0;
}

Output: “GEEKS % FOR % GEEKS”

Backslash (\) works as escape character for double quote (“). For explanation of %%, please see this.

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