强制类型转换问题，带代码，顶帖就给分，求解答，麻烦了，谢谢
main(){
int a,b;
float x;
double y;
a=355.5;
printf("a=%d\n",a);
x=57;
printf("x=%f\n",x);
y=57;
printf("y=%lf\n",y);
b=a+x;
printf("b=%f\n",b);
system("pause");
}
Otherwise, if one operand is long int and the other is unsigned int, the effect depends on whether a long int can represent all values of an unsigned int; if so, the unsigned int operand is converted to long int; if not, both are converted to unsigned long int.
Otherwise, if one operand is long int, the other is converted to long int.
Otherwise, if either operand is unsigned int, the other is converted to unsigned int.
Otherwise, both operands have type int.
[解决办法]
追问 但是问什么执行b=a+x;
printf("b=%f\n",b);
运行结果：
a=355
x=57.000000
y=57.000000
b=0.000000-------------->这里不应该是0.000000吧。
请按任意键继续. . .
我是在VS2010编译环境运行的结果啊。
求解释啊。
[解决办法]
0 1 2 3 4 5 6 7 8 9
a b c d e f
A B C D E F
integer-suffix :
unsigned-suffix long-suffixopt
long-suffix unsigned-suffixopt
unsigned-suffix : one of
u U
long-suffix : one of
l L
64-bit integer-suffix :
i64
To specify integer constants using octal or hexadecimal notation, use a prefix that denotes the base. To specify an integer constant of a given integral type, use a suffix that denotes the type.
To specify a decimal constant, begin the specification with a nonzero digit. For example:
int i = 157; // Decimal constant
int j = 0198; // Not a decimal number; erroneous octal constant
int k = 0365; // Leading zero specifies octal constant, not decimal
To specify an octal constant, begin the specification with 0, followed by a sequence of digits in the range 0 through 7. The digits 8 and 9 are errors in specifying an octal constant. For example:
int i = 0377; // Octal constant
int j = 0397; // Error: 9 is not an octal digit
To specify a hexadecimal constant, begin the specification with 0x or 0X (the case of the “x” does not matter), followed by a sequence of digits in the range 0 through 9 and a (or A) through f (or F). Hexadecimal digits a (or A) through f (or F) represent values in the range 10 through 15. For example:
int i = 0x3fff; // Hexadecimal constant
int j = 0X3FFF; // Equal to i
To specify an unsigned type, use either the u or U suffix. To specify a long type, use either the l or L suffix. For example:
unsigned uVal = 328u; // Unsigned value
long lVal = 0x7FFFFFL; // Long value specified
// as hex constant
unsigned long ulVal = 0776745ul; // Unsigned long value
C++ Floating-Point Constants
Floating-point constants specify values that must have a fractional part. These values contain decimal points (.) and can contain exponents.
Syntax
floating-constant :
fractional-constant exponent-partopt floating-suffixopt
digit-sequence exponent-part floating-suffixopt
fractional-constant :
digit-sequenceopt . digit-sequence
digit-sequence .
exponent-part :
e signopt digit-sequence
E signopt digit-sequence
sign : one of
+ –
digit-sequence :
digit
digit-sequence digit
floating-suffix :one of
f l F L
Floating-point constants have a “mantissa,” which specifies the value of the number, an “exponent,” which specifies the magnitude of the number, and an optional suffix that specifies the constant’s type. The mantissa is specified as a sequence of digits followed by a period, followed by an optional sequence of digits representing the fractional part of the number. For example:
18.46
38.
The exponent, if present, specifies the magnitude of the number as a power of 10, as shown in the following example:
18.46e0 // 18.46
18.46e1 // 184.6
If an exponent is present, the trailing decimal point is unnecessary in whole numbers such as 18E0.
Floating-point constants default to type double. By using the suffixes f or l (or F or L — the suffix is not case sensitive), the constant can be specified as float or long double, respectively.
Although long double and double have the same representation, they are not the same type. For example, you can have overloaded functions like
void func( double );
and
void func( long double );
[解决办法]
这样也带？？？？？
