This question already has answers here:
scanf() leaves the newline character in the buffer
(7 answers)
Closed 10 months ago.
My code isn't asking for the second %c input and just printing the result. of the first and printing the next question after.
This is the assignment: Students can take Programming module if they are from SOE or they have passed Math. Otherwise, they cannot take the module.
Write a program to allow students to check their eligibility. Your program must have only one if-else statement and must use the OR logical operator in the condition.
Your program must be able to produce the sample outputs given below. Note that the values underlined are the input data.
this is the code i wrote:
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
char soe, math;
printf("Are you from SOE [y/n]? ");
scanf("%c", &soe);
printf("Did you pass Math [y/n]? ");
scanf("%c", &math);
if(soe == 'y' || math == 'y'){
printf("OK, you can take Programming");
}
else{
printf("Sorry, you cannot take Programming");
}
}
Are you from SOE [y/n]? y
Did you pass Math [y/n]? OK, you can take Programming
it immediately prints the 2nd printf after the 1st input and doesnt ask for a second input
You have to use getchar() between two scanf function calls, unless they are using the %d conversion format specifier.
(This function cleans the buffer by consuming the ENTER key that you pressed after the first scanf. If you don't do it, the ENTER key still exists and the next scanf will take it as an answer.)
This way :
printf("Are you from SOE [y/n]? ");
scanf("%c", &soe);
getchar();
printf("Did you pass Math [y/n]? ");
scanf("%c", &math);
Related
This question already has answers here:
The program doesn't stop on scanf("%c", &ch) line, why? [duplicate]
(2 answers)
Closed 1 year ago.
I'm struggling on a question proving scanf() and getchar() can both retrieve a character from the input.
However, when I try to put them inside the same program, only the first function is running properly. The latter is discarded completely.
#include <stdio.h>
char letter;
int main()
{
printf("I'm waiting for a character: ");
letter = getchar();
printf("\nNo, %c is not the character I want.\nTry again.\n\n",letter);
printf("I'm waiting for a different character: ");
scanf("%c",&letter);
printf("Yes, %c is the one I'm thinking of!\n",letter);
return(0);
}
output
I have tried switching the places of those two functions but it is of no use.
Can someone help me find the issue and provide a way to fix this? The only requirement is that the program takes input twice, once by the getchar() function and once via scanf()
The second read attempt just reads whitespace (the end of line character, since you pressed enter after the first letter). Simply replace it with this:
scanf(" %c", &letter);
The space before % will tell scanf to read the next non-whitespace character.
This question already has an answer here:
How to read / parse input in C? The FAQ
(1 answer)
Closed 4 years ago.
I am trying to figure out the best way to get an integer and a character from a user
Here is what I have so far:
#include <stdio.h>
int main()
{
int a;
char b;
printf("enter the first number: \n");
scanf("%d", &a);
printf("enter the second char: \n");
scanf("%c", &b);
printf("Number %d",a);
printf("Char %c",b);
return 0;
}
The output is not shown correctly. Is there any problem with this?
Your input and output statements are fine. Just replace printf("Number %d",a); with printf("Number %d\n",a); to better format the output. Also you should change your second scanf statement to scanf(" %c", &b);. This will deal with the newline character entered after the number is inputted.
After you enter the number, you pressed the Enter key. Since the scanf function works on the input stream, when you try to process the next char after reading the number, you are not reading the character you typed, but the '\n' character preceding that. (i.e. because the Enter key you pressed added a '\n' character to your input stream, before you typed your char)
You should change your second call to scanf with the following.
scanf(" %c", &b);
Notice the added space character in the formatting string. That initial space in the formatting string helps skip any whitespace in between.
Additionally, you may want to add \n at the end of the formatting strings of both printf calls you make, to have a better output formatting.
Here you need to take care of hidden character '\n' , by providing the space before the %c in scanf() function , so the "STDIN" buffer will get cleared and scanf will wait for new character in "STDIN" buffer .
modify this statement in your program : scanf("%c",&b); to scanf(" %c",&b);
This question already has answers here:
scanf() leaves the newline character in the buffer
(7 answers)
Closed 5 years ago.
In following c code scanf is not working.
When program is run, it execute upto the second printf line and after it skips the scanf("%c",&sex); and directly execute next printf().
Why this so happen?
I run this code on different c compilers, but the output is same.
#include<stdio.h>
void main()
{
char mar,sex;
int age,flag=0;
printf("Married [Y/N]:");
scanf("%c",&mar);
printf("Sex [M/F] :");
scanf("%c",&sex); //**This not working**
printf("Age :"); //**execution directly jumped here**
scanf("%d",&age);
if(mar=='y')
flag=1;
else if(sex=='m'&& age>=30)
flag=1;
else if(sex=='f'&& age>=25)
flag=1;
else
{
}
if(flag)
{
printf("Congratulations!!!! You are Egligible..");
else
printf("Sorry... You are not egligible..");
getch();
}
//Output
Married [Y/N]:y
Sex [M/F] :Age :23
Congratulations!!!! You are Egligible..
The problem is with the new line character that you press after you enter values (Y/N) for the previous scanf. The new line character is taken as an input and the program proceeds with the next one. Try to use flushall(); before next read (that is scanf) this will solve your problem. You can also use space before the format specifier to solve this, that will escape the newline character.
This question already has answers here:
C: Multiple scanf's, when I enter in a value for one scanf it skips the second scanf [duplicate]
(7 answers)
Closed 8 years ago.
This is part of a university lab and the TA tells me there is an error but I haven't a clue. When I run it it asks me for the first char but then runs through the program and doesn't ask me at the second scanf.
#include <stdio.h>
int main(void) {
char sen, ben;
printf("Type in a character: ");
scanf("%c", &sen);
printf("The key just accepted is %d", sen);
printf("\nType in another character: ");
scanf("%c", &ben);
printf("The key just accepted is %d", ben);
}
Actually this is C not C++. Save it as file.c.
Try this:
#include <stdio.h>
int main(void) {
char sen, ben;
printf("Type in a character: ");
sen = getchar();
printf("The key just accepted is %d", sen);
printf("\nType in another character: ");
getchar();
ben = getchar();
printf("The key just accepted is %d", ben);
}
Explanation: when you enter the first character and press enter it takes enter's ASCII code as the second.
I suggest not to use scanf. But it works both ways if you put a getchar to "take" the enter.
Adding a space before %c in the second scanf will solve the issue.
This is done because scanf does not consume the \n character after you enter the first character and leaves it in the stdin.As the Enter key(\n) is also a character,it gets consumed by the next scanf call.The space before the %c will discard all blanks like spaces.
When you are scanning a character(%c) using scanf,add a space before %c as it would help reduce confusion and help you. Therefore, in both the scanfs , you can add the space.
When you pressed your key and then hit enter, you typed in two keys. The first was the desired key ,a for example, and the second was the key <enter> typically written as \n. So, your second scanf captures the result \n.
Since printing out the \n character doesn't result in something that is easy to see on the screen, it will appear like your program is just skipping the second scanf and printing out only the fixed parts of the printf without a easily viewable value.
One way to get around this problem is to consume all the key strokes just before the key you want to capture. This is done by accepting more input after the character up until you see a newline character \n. Once you see that character, then you do your next read.
// flush extra input up the to carriage return
char flush = 0;
while (flush != '\n') {
scanf("%c", &flush);
}
// now read my desired input
scanf("%c", &ben);
that's because nobody accepts '\n'. call scanf like this scanf("%c%*c", &sen). %*c means you want to omit one character, which is '\n'.
btw, void main() is allowed. main function is not the real entry point of executable, so it's ok to do that. but it seems not everybody likes it.
This question already has answers here:
Yes/No loop in C
(3 answers)
Closed 8 years ago.
I am trying to execute a small program using do-while.
#include<stdio.h>
#include<conio.h>
void main()
{
char another;
int num;
do
{
printf("Enter a number");
scanf("%d",&num);
printf("Square of %d id %d",num,num*num);
printf("Want to another another number y/n");
scanf("%c",&another);
}while(another=='y');
}
Now when I try to execute the program, it runs fine. I input a number and it displays its square. And then I see Want to enter another number y/n. But as soon as I press any key (y or n), the program exits itself before I can press enter to provide the input. I tried it many times but no success.
But the program runs fine if I ask the user to input either 1 or 2(in place of y/n). In that case it takes an integer input and can check the while block. If another == 1, the program runs again.
My problem is that why can't I check for a character in the while condition.
The reason it doesn't work is that after scanf gets num, the new line is still in the buffer, so it will be processed by the next scanf with %c format specifier. A direct way of fixing it is to use:
scanf(" %c", &another);
// ^space
Note that your original scanf("%c:,&another); won't compile, but I assume that's a typo. And always use int main, or it's undefined behavior.