Aspect | Signed Integers | Unsigned Integers |
---|---|---|
Range | Can represent both negative and positive values | Only represents non-negative values |
Typical Range | -2,147,483,648 to 2,147,483,647 (for int ) | 0 to 4,294,967,295 (for unsigned int ) |
Bit Representation | Uses one bit for the sign (positive or negative) | Uses all bits for the value |
Default Type | Default type for integers if not specified | Explicitly specified as unsigned |
Syntax | int , signed int | unsigned int , unsigned char , unsigned long |
Typical Use Cases | When you need to represent both negative and positive numbers | When you need to represent only positive numbers or require a larger positive range |
Example Range for char | -128 to 127 (for signed char ) | 0 to 255 (for unsigned char ) |
Example Range for short | -32,768 to 32,767 (for signed short ) | 0 to 65,535 (for unsigned short ) |
Overflow Behavior | Overflow wraps around within the negative range | Overflow wraps around starting from zero |
Memory Usage | Uses the same amount of memory as unsigned integers (e.g., int and unsigned int are usually 4 bytes) | Uses the same amount of memory as signed integers (e.g., unsigned int and int are usually 4 bytes) |
Key Points
- Range: Signed integers can hold both positive and negative values, while unsigned integers only hold non-negative values. As a result, unsigned integers can typically represent a larger positive range compared to their signed counterparts.
- Bit Representation: Signed integers use one bit to represent the sign of the number (positive or negative), which reduces the amount of space available for representing the magnitude. Unsigned integers use all available bits for the magnitude.
- Default Behavior: By default, if you declare an integer without specifying it as
signed
orunsigned
, it is assumed to be signed. - Overflow: Overflow behavior is different between signed and unsigned integers. In signed integers, overflow can result in wrapping from the negative side, while in unsigned integers, it wraps around from zero.
Understanding these differences is important for choosing the appropriate integer type based on the needs of your program, especially when dealing with ranges of values and the potential for overflow.