Character Array MCQ 4 : String Length and Pointer



Character Array MCQ 4 : String Length and Pointer


When I was Selected for Technical Interview of Accenture then Technical Person Asked me –
Predict the Output of the Following Program ?

#include<stdio.h>
int main()
{
char str[]="c4learn";

printf("%d",*(str+strlen(str)));

return(0);
}

Options :

  1. 0
  2. NULL Character
  3. Garbage
  4. None Of these

Output:


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How and Why ?
Consider –

*( str + strlen(str))
= *( str + 7)
= *( Base Address of str + 7)
  • Base Address Means Address of str[0].
  • str[0] + 7 means ‘NULL Character
  • Length of Array is 7 –
str[0] = 'c'
str[1] = '4'
str[2] = 'l'
str[3] = 'e'
str[4] = 'a'
str[5] = 'r'
str[6] = 'n'
str[7] = '\0'

So

*(str + strlen(str)) Returns NULL Character '\0'

Look at Printf Statement Once Again –

  1. %d is Written inside Printf
  2. So ASCII Value of ‘\0’ will be printed.
  3. ASCII Value of ‘\0’ is 0.