- 1 year ago
Why scanf overrides previously readed unsigned char variables with 0?
The behavior you described, where scanf
overrides previously read unsigned char
variables with 0, can happen when there is a mismatch between the format specifier used in scanf
and the actual data type of the variables being read.
The scanf
function in C requires format specifiers to match the data types of the variables being read. If the format specifier does not match the data type of the variable, it can cause undefined behavior, leading to unexpected results like overriding the values of other variables.
In your case, if you are reading unsigned char
variables, you should use the correct format specifier for unsigned char
, which is %hhu
in the scanf
function. The %hhu
format specifier is used to read an unsigned char
.
Here's an example of how to use scanf
to read unsigned char
variables correctly:
c#include <stdio.h>
int main() {
unsigned char var1, var2;
printf("Enter two unsigned char values: ");
scanf("%hhu %hhu", &var1, &var2);
printf("var1: %u\n", var1);
printf("var2: %u\n", var2);
return 0;
}
In this example, the %hhu
format specifier is used to read two unsigned char
values from the user, and the values are then printed to the console. The %hhu
specifier ensures that the correct data type is read from the input, and there will be no unintended overwriting of other variables.
Make sure to use the appropriate format specifiers for the data types you are reading with scanf
to avoid such issues.