CODEWITHSUNDEEP
cloopsinputwhile-loopscanf
Addison Montgomery
Addison Montgomery

Reputation: 351

Checking if the user entered an int - C

I need to check if the user entered a integer in a scanf() (in C). I have this code:

do {
    srs = scanf("%d", &x);
} while (!srs);

If I enter a number it works and continues with the program, but if I enter a char, it just asks me for input again. Though, if then of this I enter a correct integer, it don't break the loop.

Upvotes: 0

Views: 307

Answers (1)

Random832
Random832

Reputation: 39000

When you don't enter the number first, it leaves the non-numeric character on the input stream for the next call to pick up. So you get in an infinite loop.

You should be using fgets to read a whole line of input, then sscanf on that input line.

do {
    char line[512];
    fgets(line,512,stdin);
    srs = sscanf(line,"%d", &x);
} while (!srs);

Upvotes: 1

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