这个类printf的tiny_printf怎么无法输出float类型？

[独孤九剑贰]

#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
void tiny_printf(char *format,...)
{
	int i;
	va_list ap;

	va_start(ap,format);
	for(i=0;format[i]!='\0';i++)
	{
		switch(format[i])
		{
		case 's': 
			printf("%s ",va_arg(ap,char *));
			break;
		case 'd':
			printf("%d ",va_arg(ap,int));
			break;
		case 'c':
			printf("%c ",va_arg(ap,char *));
			break;
		case 'f':
			printf("%f ",va_arg(ap,float));
			break;
		default:
			assert(0);
		}
	}
	va_end(ap);
	putchar('\n');
}

int main(void)
{
	tiny_printf("ssdcf","result is you are SB","is",33,'i',2.3);
	return 0;
}

[图灵狗]

		case 'c':
			printf("%c ",(char)va_arg(ap,int));
			break;
		case 'f':
			printf("%f ",(float)va_arg(ap,double));
			break;

引用 楼主 abc594986308 的回复:

#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
void tiny_printf(char *format,...)
{
	int i;
	va_list ap;

	va_start(ap,format);
	for(i=0;format[i]!='\0';i++)
	{
		switch(format[i])
		{
		case 's': 
			printf("%s ",va_arg(ap,char *));
			break;
		case 'd':
			printf("%d ",va_arg(ap,int));
			break;
		case 'c':
			printf("%c ",va_arg(ap,char *));
			break;
		case 'f':
			printf("%f ",va_arg(ap,float));
			break;
		default:
			assert(0);
		}
	}
	va_end(ap);
	putchar('\n');
}

int main(void)
{
	tiny_printf("ssdcf","result is you are SB","is",33,'i',2.3);
	return 0;
}

[赵4老师]

tiny_printf("ssdcf","result is you are SB","is",33,'i',2.3f); 常量也有类型！ 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 ); C++ Integer Constants Integer constants are constant data elements that have no fractional parts or exponents. They always begin with a digit. You can specify integer constants in decimal, octal, or hexadecimal form. They can specify signed or unsigned types and long or short types. Syntax integer-constant : decimal-constant integer-suffixopt octal-constant integer-suffixopt hexadecimal-constant integer-suffixopt 'c-char-sequence' decimal-constant : nonzero-digit decimal-constant digit octal-constant : 0 octal-constant octal-digit hexadecimal-constant : 0x hexadecimal-digit 0X hexadecimal-digit hexadecimal-constant hexadecimal-digit nonzero-digit : one of 1 2 3 4 5 6 7 8 9 octal-digit : one of 0 1 2 3 4 5 6 7 hexadecimal-digit : one of 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