CODEWITHSUNDEEP
cscanf
Dezhou Zhang
Dezhou Zhang

Reputation: 169

scanf("%c") call seems to be skipped

I tried this code below, but it seems scanf("%c") is skipped. It only asks me to enter name and age and skips the lines below that. It just print the text in the printf above the if statements. Can anyone help?

#include<stdio.h>

int main()
{
    int age;
    char sex;
    char name[20];
    char status;
    printf("Enter your last name\n");
    scanf("%s", &name);

    printf("Enter your age\n");
    scanf("%d", &age);

    printf("Enter sex (M/F)\n");
    scanf("%c", &sex);

    printf("your status,married, single,irrelevant (M/S/I)\n");
    scanf("%c", &status);
    if(age>=16 && sex=='M')
        printf("hello, Mr %s\n", name);
    if(age<16 && sex =='M')
        printf("hello, Master %s\n", name);
    if(sex=='F' && status=='M')
        printf("hello, Mrs %s\n", name);
    if(sex=='F' &&(status=='S' ||status=='I'))
        printf("hello,miss %s\n", name);
}

Upvotes: 7

Views: 24138

Answers (5)

Shunya
Shunya

Reputation: 20

This happens because blankspace is also treated as a character and and happens when you press enter. So Leave a space.

scanf(" %c",&something);

Upvotes: 0

Peter - Reinstate Monica
Peter - Reinstate Monica

Reputation: 16017

Unless you are interested in whitespace like newlines, do not use %c. Simply use the string conversion %s and use the first character of the input.

Rationale: All scanf conversion specifiers except %c ignore white space including newlines. They are designed to read sequences of input tokens (numbers, words) where the amount and nature of white space is irrelevant. The words can all be on the same line, or each word on a different line; scanf wouldn't care unless you force single character reads with %c which is almost never necessary.

Upvotes: 1

Ayushi Jha
Ayushi Jha

Reputation: 4023

Change your code to 

#include<stdio.h>
int  main()
{
int age;
char sex;
char name[20];
char status;
printf("Enter your last name\n");
// scanf("%s", &name);
fgets(name,20,stdin);

printf("Enter your age\n");
scanf("%d", &age);

printf("Enter sex (M/F)\n");
scanf(" %c", &sex);


printf("your status,married, single,irrelevant (M/S/I)\n");
scanf(" %c", &status);
if(age>=16 && sex=='M')
printf("hello, Mr %s\n", name);
if(age<16 && sex =='M')
printf("hello, Master %s\n", name);
if(sex=='F' && status=='M')
printf("hello, Mrs %s\n", name);
if(sex=='F' &&(status=='S' ||status=='I'))
printf("hello,miss %s\n", name);
return 0;
}

Here, I have added an extra space before the format specifier %c, to accommodate any previous input like newline (\n).
Another alternative method is to use getchar() immediately before you take any character input.

Also, if you perform string input with scanf, it will not read the input after encountering a whitespace. So, instead use fgets for taking any string input which might contain spaces.

Another thing I changed in your code (trivial) is int main() and return 0.

Upvotes: 0

Arun A S
Arun A S

Reputation: 7006

Change 

scanf("%c", &sex);

to

scanf(" %c", &sex);
       ^
      space

and 

scanf("%c", &status);

to

scanf(" %c", &status);
       ^
      space

The problem is because of trailing newline characters after your second call to scanf(). Since it is of %d type specifier, when you press Enter A newline character ( '\n' ) is left in the stream and the next scanf() tries to read that newline character, and thus, it seems as though it just skipped input, but in fact, it read the newline character.

So, the newline character is stored in the variable sex, and thus, it skips asking you for input for that variable.

Upvotes: 24

ForceBru
ForceBru

Reputation: 44828

You can do the following for all scanfs. 

scanf("%c\n",&smth);

And then enter the values one by one separating them by newlines (press Enter).

This helped me too when I had the same problem. 

scanf("%c*",&smth);

That makes scanf skip any other characters that a user might input, including newlines.

Note: use appropriate format strings for each type (%s for strings, %d for integers, etc).

Upvotes: -1

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