where is the problem?

[r3zaneo]

after i run the program, when i enter an integer number it asks me to calculate V for velocity or T for time but when i enter v or t id does not accept it




Write a complete C program that performs gravity calculations based on Isaac Newton's law of universal gravitation. Your program must do this:

1. How long (in seconds – 2 decimal places) does it take an object to fall distance d? (d, in meters, being entered by the user at the keyboard).
2. What is the velocity (in meters per second – 2 decimal places) of an object that has traveled d meters?
3. Ask the user for the desired computation (1) for time, (2) for velocity and (3) to end program.
4. Your program must return to the choices until the user enters option (3).

int
main()

{
char variable;
int d= 0.0;
float sqvelocity =0.0;
float sqtime =0.0;

printf("Enter a value for distance:");
scanf("%d",&d);

printf("Enter variable for desired computation, v (velocity) or t (time):");
scanf("%c", &variable);

if (variable == 'v')
printf("the velocity is: %lf.\n", sqvelocity);
else
if (variable == 't')
printf("the time is: %lf.\n", sqtime);

sqvelocity= sqrt(2*9.8*d);
sqtime= sqrt((2*d)/9.8);

return (0);
}

Hello admins would you delete my post.
NO!

Thanks

[anduril462]

After you type in the distance, you hit enter. That enter puts a new line ('\n') character in the input buffer. That '\n' is not a number, so %d doesn't read it, it leaves it there. Then when you call scanf("%c", &variable), the %c reads the next character, the new line, not the 'v' or 't' you type. Read this post (soon to be a FAQ article here) for more info and possible solutions: http://cboard.cprogramming.com/c-pro...ml#post1126782.

The quick fix is to put a space before the %c:

scanf(" %c", &variable);

The space skips any whitespace (space, tab, vertical tab, newline).

[Matticus]

Your main problem is that, when you enter the distance, you type a number and press enter - there are now two objects in the input stream - the integer, and the newline character. For instance,

4\n

The newline remains in the input buffer, and is picked up by the next "scanf()", giving the appearance that the second "scanf()" was skipped.

One way around it is to tell the second "scanf()" to skip any leading whitespace - this can be done by placing a space before the format specifier:

scanf(" %c",&variables);

Some other observations:

- If 'd' is an integer, just assign it 0 (and not 0.0)
- You're printing out "sqvelocity" and "sqtime" before they are calculated

[EDIT] Too slow again!

[r3zaneo]

Thanks

[Click_here]

Hello admins would you delete my post.

You shouldn't have deleted your code in #1. Your problem may have helped someone else.

[Salem]

Fixed