的printf（无符号：％U \\ N，uEntry）;
// ^^
 

您必须使用％U 符告诉的printf 运行时的 uEntry 是 unsigned int类型。如果你使用％d个的的printf 函数会期待一个 INT ，从而reinter preT你输入回一个签名的值。

Actually I've (probably) a "simple" problem. So I don't know how to cast a signed integer to an unsigned integer.

My code :

signed int entry = 0;
printf("Decimal Number : ");
scanf("%d", &entry);
unsigned int uEntry= (unsigned int) entry;
printf("Unsigned : %d\n", uEntry);

If I send the unsigned value to the console (see my last code line), I always get back an signed integer.

Can you help me?

Thanks a lot!

Kind regards, pro

printf("Unsigned : %u\n", uEntry);
//                 ^^

You must use the %u specifier to tell the printf runtime that the uEntry is an unsigned int. If you use %d the printf function will expect an int, thus reinterpret your input back to a signed value.