Thread: Need help in C

Hi, nabhatt. I've written a code that partially does what I think you wanna do. The explanation for it is right after the code, shown right below:

Code:

#include <stdio.h>

int main(void)
{
    /* Declaration of variable x: */
    int x;

    /* Data input: */
    printf("Enter the value of x: ");
    scanf("%d", &x);

    /* [01]: */
    printf("%f", (double)x);

    /* 2 new lines: */
    printf("\n\n");

    /* [02]: */
    printf("%X", x);

    /* 2 new lines: */
    printf("\n\n");

    /* [03]: */
    printf("%p", &x);

    return 0;
}

The code starts with the C preprocessor directive

Code:

#include <stdio.h>

which is necessary in order to use the functions scanf() and printf(). The program starts (and ends) its execution in function main(), which starts with

Code:

int main(void)
{

and ends with

Code:

return 0;
}

Right after the beginning of function main(), x is declared as an int variable:

Code:

int x;

Then, printf() asks for the user to input a value for x, which is then read by scanf(), all this happening in the following statements:

Code:

printf("Enter the value of x: ");
scanf("%d", &x);

The first printing of x is as a decimal-point number. x is an int variable, so, in order to print it as decimal number (with %f), you must first assign it to a double variable (say, for example, double y) and print y instead of x, or you can use the type cast to float or double (as is done in the following code) to print x as a number with decimal point. This is a temporary conversion - after this printf statement, x will still maintain its value acquired during the input above.

Code:

printf("%f", (double)x);

In order to accomplish the second printing, which is outputting x in the hexadecimal base, you just use %X instead of %f, and you don't do a type conversion this time:

Code:

printf("%X", x);

The third printf() statement means to print the value of &x, where & is the address operator. &x is the address in memory of the variable x; in order to print an address, you can use the %p specifier:

Code:

printf("%p", &x);

The output is the address of variable of x in hexadecimal format.

If you still need help, please let us know.