What does the suffix u mean in c language

The suffix u in C language represents an unsigned integer, which is used to prevent overflow errors and only represents non-negative values. Represents a bit mask to facilitate bitwise operations. Represents the index, ensuring non-negative values.

The meaning of suffix u in C language

In C language, suffix u is used to indicate unsigned integer . Unsigned integers are integer variables that can only represent non-negative values.

Purpose

The suffix u is mainly used in the following situations:

• Prevent overflow errors:When the pair is signed An overflow error may occur when an integer is cast. Using unsigned integers avoids this problem because it cannot represent negative values.
• Representing bit masks: Unsigned integers are often used to represent bit masks because they can easily perform bitwise operations with other integers.
• Represents index: Unsigned integers are often used to represent indexes of arrays and strings because they cannot be negative.

Comparison with signed integers

Compared with signed integers, unsigned integers have the following characteristics:

• Range: The range of unsigned integers is 0 to 2^n-1, where n is the number of bits of the integer type. Signed integers range from -2^(n-1) to 2^(n-1)-1.
• Bitwise operations: Unsigned integers can perform all bitwise operations, while signed integers can only perform certain specific bitwise operations.
• Type conversion: When converting from a signed integer type to an unsigned integer type, positive values ​​will be retained, and negative values ​​will be truncated and turned into positive values.

Example

The following example demonstrates the use of the suffix u:

<code class="c">unsigned int x; // 无符号整数变量

x = 100; // 将 100 赋值给 x，因为 x 是无符号整数，所以它不会产生溢出错误

int y; // 有符号整数变量

y = x; // 将 x 转换为有符号整数并赋值给 y。如果 x 大于 y 的最大值，则会发生溢出错误</code>

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