CODEWITHSUNDEEP
cstring
Gagan Batra
Gagan Batra

Reputation: 52

Why am I not getting the concatenated string?

I have written this code where I want to add two integers, two doubles and concatenate two strings out of which one of the integer, double and the string is already declared and the other integer, string and double are to be taken by the user. But it seems that the program isn't taking another string as an input.

I have written a similar program where I can take the string from the user using scanf but the same isn't working here.

int main() {
int i = 4;
double d = 4.0;
char s[] = "My college name is  ";

// Declare second integer, double, and String variables.
int i2,sum1;
double d2,sum2;
char s2[100];

// Read and save an integer, double, and String to your variables.
scanf("%d",&i2);
scanf("%lf",&d2);
scanf("%[^\n]%*c",&s2);

sum1= i+i2;
sum2= d+d2;
strcat(s,s2);

// Print the sum of both integer variables on a new line.
printf("%d\n",sum1);
printf("%.1lf\n",sum2);
printf("%s",s);


return 0;}

After I made the necessary changes like removing & from s2 and changing s[] to s[200], I still cannot get the concatenated string. I am writing my edited code. Kindly help me with that.

int main() {
int i = 4;
double d = 4.0;
char s[200] = "My college name is  ";


// Declare second integer, double, and String variables.
int i2,sum1;
double d2,sum2;
char s2[100];

// Read and save an integer, double, and String to your variables.
scanf("%d",&i2);
scanf("%lf",&d2);
scanf("% [^\n]%*c",s2);

sum1= i+i2;
sum2= d+d2;
strcat(s,s2);

// Print the sum of both integer variables on a new line.
printf("%d\n",sum1);
printf("%.1lf\n",sum2);
printf("%s",s);


return 0;
}

Kindly help me with the bug here.

Upvotes: 2

Views: 176

Answers (4)

Niloy Rashid
Niloy Rashid

Reputation: 707

It's not taking your string input because you use %[^\n]%*c to scan the string. which instuct the program to return after geting a newline as input. And the string got a newline form the buffer after scanning d2, and return with out taking further input.

To get rid of this you need to input a char before taking the input of the string. Change the following lines:

scanf("%lf",&d2);
scanf("%[^\n]%*c",&s2);

To:

scanf("%lf",&d2);
getchar();
scanf("%[^\n]%*c",&s2);

And your code will take the string input properly.

Additionally, you can also do this (taking a extra character input befor string input) by putting a extra space before % sign.

Changing the following line: 

scanf("%[^\n]%*c",&s2);

To:

scanf(" %[^\n]%*c",&s2);

Also do the same thing.

Upvotes: 2

user11493159
user11493159

Reputation: 186

Replace:

scanf("%[^\n]%*c",&s2);

With:

fgetc(stdin);   
fgets(s2, 100,stdin);

Upvotes: 1

Callum Kavanagh
Callum Kavanagh

Reputation: 39

Possibly your use of 

scanf("%[^\n]%*c",&s2);

As far as I'm aware you can use 

scanf("%[^\n]%*c",s2);

or 

scanf("%[^\n]%*c",&s2[0]);

As the variable s2 is itself a pointer to the first memory address of the array, using &s2 is just a pointer to a pointer and has no allocated consecutive memory addresses to fill. Hope this helps.

Upvotes: 1

One Guy Hacking
One Guy Hacking

Reputation: 1291

You are passing the wrong type of argument to scanf. s2 is an array of chars, so &s2 is a pointer to an array of chars, not a pointer to a char.

(You also ought to have bounds checking to prevent array overflows, add a newline to your final printf, etc. But eliminating the & will make your program compile and run)

Upvotes: 2

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