隐式签名到无符号警告

您好，我很少关注隐式签名到无符号转换警告。为什么所有的变量都被声明为无符号，我仍然得到这个警告？上面例子中的值是否被视为无符号或有符号字符？在这种情况下，变量“C”的值是150还是其他？同样，在下一个示例中，变量在下面的表达式中实际如何处理？如果变量“b2”可能被当作符号char而不是未签名，结果会大不相同，因此我需要理解这一点。



      以下为原文

    Hello I have few concerns on implicit signed to unsigned conversion warning. Why do I keep getting this warning even though all the variables are declared as unsigned?

unsigned char a = 70;
unsigned char b = 2;
unsigned char c = 10;

c += a * b; // warning: (373) implicit signed to unsigned conversion
Does the value in the example above will be treated as unsigned or signed char? In this case will the value of variable "c" be 150 or something else?

Similarly in the next example, how are the variables actually treated in the expression below? If the variable "b2" might get treated as signed char instead of unsigned, the outcome would be much different hence I need to understand this.

unsigned char a2 = 0;
unsigned char b2 = 202;
unsigned char c2 = 203;
unsigned char d2 = 204;
unsigned char e2;
   
e2 = a2 < b2 ? c2 : d2; //warning: (373) implicit signed to unsigned conversion