CODEWITHSUNDEEP
cloopsfor-loop
Mackenzie Binns
Mackenzie Binns

Reputation: 23

How can I exit a loop using a single scanf function that is already taking inputs?

I am making a program for some friends and myself that calculates grades with the weighted percentage and what grades need to me made on the final to pass the class with a specified grade.

The for loop in question is this, 

for(;;)
{
    scanf("%f", &s->grade);
    if(s->grade == 'x')
    {
        break;
    }else{
        grade += s->grade;
    }
}

how can I make this exit through the use of a letter rather than a number?
If you need any more code feel free to ask.

Upvotes: 0

Views: 81

Answers (4)

Jim Balter
Jim Balter

Reputation: 16406

char buf[100];

while (fgets(buf, sizeof buf, stdin) && *buf != 'x')
{
    sscanf(buf, "%f", &s->grade); // should check return value of sscanf to see if the input was correct
    grade += s->grade;
}

Upvotes: 0

fingaz
fingaz

Reputation: 231

So I believe that you're asking for a percentage received from somewhere and want to convert that to a letter grade.

If so, I would receive the percentage either from another function passed into the code you have or read from a file.

Then, I would create a switch statement which takes the value received. Truncate it to an int. Then, cast that char you want for the given value. Take that char and bring it into the function you have.

Scanf("%f", x);

Function(x){ Switch(x){ Case 90: (Char*)x = 'a'; Return x; ... }

Upvotes: 0

Dwayne Towell
Dwayne Towell

Reputation: 8583

Either check the return value of scanf--EOF means nothing was parsed/scanned.

Or, use a two step process. First, read a string and check if it equals "x" or whatever, it not, use sscanf to convert the string into a float.

Upvotes: 3

Alexandre Santos
Alexandre Santos

Reputation: 8338

You are already asking for a floating point number, and you are checking this against the char 'x', so just replace the 'x' with the value you want or do it in an or.

Upvotes: 0

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