Online C Programming Test - C Programming Test - Random

The difference is that text files contain lines (or records) of text and each of these has an end-of-line marker automatically appended to the end of it whenever you indicate that you have reached the end of a line.

Binary files are not broken up into separate lines or records so the end-of line marker is not written when writing to a binary file.

So, we cannot read the correct the data in binary mode.

Step 1: int fun(int); Here we declare the prototype of the function fun().

Step 2: int i = fun(10); The variable i is declared as an integer type and the result of the fun(10) will be stored in the variable i.

Step 3: int fun(int i){ return (i++); } Inside the fun() we are returning a value return(i++). It returns 10. because i++ is the post-increement operator.

Step 4: Then the control back to the main function and the value 10 is assigned to variable i.

Step 5: printf("%d\n", --i); Here --i denoted pre-increement. Hence it prints the value 9.

The scanf function returns the number of input is given.

printf("%d\n", scanf("%d", &i)); The scanf function returns the value 1(one).

Therefore, the output of the program is '1'.

A label is used as the target of a goto statement, and that label must be within the same function as the goto statement.

Syntax: goto <identifier> ;
Control is unconditionally transferred to the location of a local label specified by <identifier>.
Example:

#include <stdio.h>
int main()
{
    int i=1;
    while(i>0)
    {
        printf("%d", i++);
        if(i==5)
          goto mylabel;
    }
    mylabel:
    return 0;
}
 

Output: 1,2,3,4

The fp is a structure which contains a char pointer which points to the first character of a file.

Note the below statement inside the struct:

int bit1:1; --> 'int' indicates that it is a SIGNED integer.

For signed integers the leftmost bit will be taken for +/- sign.

If you store 1 in 1-bit field:

The left most bit is 1, so the system will treat the value as negative number.

The 2's complement method is used by the system to handle the negative values.

Therefore, the data stored is 1. The 2's complement of 1 is also 1 (negative).

Therefore -1 is printed.


If you store 2 in 4-bits field:

Binary 2: 0010 (left most bit is 0, so system will treat it as positive value)

0010 is 2

Therefore 2 is printed.


If you store 13 in 4-bits field:

Binary 13: 1101 (left most bit is 1, so system will treat it as negative value)

Find 2's complement of 1101:

1's complement of 1101 : 0010
2's complement of 1101 : 0011 (Add 1 to the result of 1's complement)

0011 is 3 (but negative value)

Therefore -3 is printed.

Step 1: char mybuf[] = "India"; The variable mybuff is declared as an array of characters and initialized with string "India".

Step 2: char yourbuf[] = "BIX"; The variable yourbuf is declared as an array of characters and initialized with string "BIX".

Step 3: char *const ptr = mybuf; Here, ptr is a constant pointer, which points at a char.

The value at which ptr it points is not a constant; it will not be an error to modify the pointed character; There will be an error only to modify the pointer itself.

Step 4: *ptr = 'a'; The value of ptr is assigned to 'a'.

Step 5: ptr = yourbuf; Here, we are changing the pointer itself, this will result in the error "cannot modify a const object".

FALSE

Example: #define symbol replacement

When the preprocessor encounters #define directive, it replaces any occurrence of symbol in the rest of the code by replacement. This replacement can be an statement or expression or a block or simple text.

Initially variables a = 500, b = 100 and c is not assigned.

Step 1: if(!a >= 400)
Step 2: if(!500 >= 400)
Step 3: if(0 >= 400)
Step 4: if(FALSE) Hence the if condition is failed.
Step 5: So, variable c is assigned to a value '200'.
Step 6: printf("b = %d c = %d\n", b, c); It prints value of b and c.
Hence the output is "b = 100 c = 200"