scanf 输入十六进制

Here, we have to declare an unsigned int variable and input a value in hexadecimal format.

在这里，我们必须声明一个无符号的int变量，并以十六进制格式输入一个值。

To input a value in hexadecimal format – we use "%x" or "%X" format specifier and to print the value in hexadecimal format – we use same format specifier "%x" or "%X".

要以十六进制格式输入值-我们使用“％x”或“％X”格式说明符并以十六进制格式打印值-我们使用相同格式的说明符“％x”或“％X” 。

• "%x" – prints value with lowercase alphabets (a to f)

  “％x” –用小写字母(a至f)打印值

• "%X" – prints value with uppercase alphabets (A to F)

  “％X” –用大写字母(A到F)打印值

Note: In scanf(), you can use both of the format specifiers "%x" or "%X" – it does not affect to user input, but in the printf() – "%x" or "%X" matters for printing alphabets in hexadecimal value (a to f or A to F).

注意：在scanf()中 ，可以同时使用格式说明符“％x”或“％X” –它不会影响用户输入，但是在printf()中 – “％x”或“％X”很重要用于以十六进制值(a到f或A到F)打印字母。

Program 1:

程序1：

#include <stdio.h>

int main(void) 
{
	unsigned int value;

	//input "123afc"
	printf("Enter hexadecimal value without \"0x\": ");
	//using %x (small x)
	scanf("%x", &value);
	printf("value = 0x%x or 0X%X\n", value, value);

	//input "123AfC"
	printf("Enter hexadecimal value without \"0X\": ");
	//using X (capital x)
	scanf("%X", &value);
	printf("value = 0x%x or 0X%X\n", value, value);

	return 0;
}

Output

输出量

Enter hexadecimal value without "0x": 123afc
value = 0x123afc or 0X123AFC
Enter hexadecimal value without "0X": 123AFC
value = 0x123afc or 0X123AFC

Program 2: Testing program with invalid hexadecimal value

程序2：测试程序的十六进制值无效

#include <stdio.h>

int main(void) 
{
	unsigned int value;

	//testing with invalue value 
	//while input, we are using alphabets 
	//which are greater than F 
	//as we know, hexadecimal allowes only 
	//A to F / a to f - which are equivelant
	//to 10 to 15

	printf("Enter a hexadecimal value: ");
	scanf("%x", &value);
	printf("value = %x\n", value);

	return 0;
}

Output

输出量

Enter a hexadecimal value: 123apd
value = 123a

Explanation:

说明：

In the hexadecimal value 123apd, "p" is not a hexadecimal digit, thus, the input is valid/acceptable till valid digits. Given input 123pad is considered as 123a.

在十六进制值123apd中 ， “ p”不是十六进制数字，因此输入直到有效数字都是有效/可接受的。 给定输入123pad被视为123a 。

翻译自: https://www.includehelp.com/c-programs/input-a-hexadecimal-value-using-scanf.aspx

scanf 输入十六进制