Difference Between Signed and Unsigned (With Table)

The difference between signed and unsigned data categories is that while the former includes both positive and negative integers, the latter solely includes positive integers. In computer programming, these ‘signed’ and ‘unsigned’ categories refer to variables that can contain certain types of integers. In the context of coding, the former category can hold both types of integers, while the latter category can solely encompass the number zero and the entire list of positive integers.

Flag signs are used by the signed category of representation to connote negative integers. Unsigned data categories do not use such signs as they can only include zero and all other positive values. The ‘signed’ and ‘unsigned’ distinction is important for a computer application to function properly. 

Comparison Table Between Signed and Unsigned

Parameters of ComparisonSignedUnsigned
Values IncludedSigned data categories include both positive and negative integers.Unsigned data categories include only zero and other positive integers. They cannot include negative integers.
MagnitudeSigned integers have a smaller magnitude than their unsigned counterparts of the same range.Unsigned integers have a greater magnitude than their signed counterparts of the same range.
Flag SignSigned data types use a flag sign before the negative numbers they represent.Unsigned data types do not use a flag sign before numbers, as they only represent positive integers.
Process of IdentificationThe leftover bit is used by the signed data containers.The leading bit of a value is used by the unsigned data containers.
Range in CharSigned integers range from -128 to 127 in chars.Unsigned integers range from 0 to 255 in chars.
Representation Method1’s complement form, 2’s complement form, and the sign-magnitude form methods can be used to represent signed binary variables.Unsigned binary variables do not have a preceding sign or symbol, and thus, there exists only one representation method for such binary variables.
Unambiguous Method of Representation1 out of 3 possible methods of representations is unambiguous.The only method of representation available is an unambiguous one.

What is Signed?

Signed number representation is the categorization of positive as well as negative integers. Signed data groupings comprise of numbers on both sides of the number line. The negative numbers are distinguished from the positive ones by flag signs.

Signed number groupings are used in computer programming. There are three methods of representing signed data sets. Under the sign-magnitude method, one bit is reserved for the sign symbol. This makes it an ambiguous method.

Similarly, the 1’s complement method is also an ambiguous method of representation of signed integers. The 2’s complement method is the only unambiguous method that can be used to represent these integers. Such data types have been extensively used in the development of programming languages like C and C+.

What is Unsigned? 

Unsigned data categorizations are essentially classifications of positive integers. They exclusively contain positive values. Zero is also a part of the unsigned categorization. Unsigned data sets do not have flag signs preceding the included integers as all the values are positive.

Like signed binary integers, the unsigned ones are also used in the domain of programming. C++, C#, and other programming languages use these data sets. In char, unsigned binary integers range from 0 to 255.

Unsigned data types can only represent the magnitude of the binary number they represent. This connotes that each number has only one binary equivalent form. Hence, this form of representation is called the unambiguous method of representation. Moreover, unsigned variables have twice the magnitude of their signed counterparts of the same range.

Main Differences Between Signed and Unsigned

  1. The main difference between signed and unsigned data types is that the former allows the user to represent both positive and negative numbers, while the latter is used to represent zero and other positive numbers. Negative numbers cannot be represented by unsigned data types. They can be exclusively used for positive integers.
  2. Although similar types of signed and unsigned variables have the same range, the latter represents a larger magnitude of the number than the corresponding signed variable.
  3. A signed data categorization uses a flag sign before the negative numbers it represents. No such flag sign is used by the unsigned data category as it only represents positive numbers.
  4. The two categories also differ in terms of their individual ranges in the context of char. Signed integers range from -128 to 127 in chars, while unsigned integers range from 0 to 255 in chars.
  5. Another difference between the two is the method of identification each uses. The leading bit of a given value is used as a part of the value by the unsigned data category to identify whether the number is positive or negative. Alternatively, signed data types use the leftover bit to make the same identification.
  6. 1’s complement method, 2’s complement method, and the sign-magnitude form method can be used to represent signed variables, as some binary variables have a negative flag sign. While the binary variables of the unsigned category solely represent their magnitudes as they are all positive integers.
  7. Signed binary integers have three possible representation techniques but only one unambiguous representation method, while unsigned binaries have one method of representation that is in turn unambiguous.

Conclusion

Binary codes are used for programming. They are also used by computers to store and access data. Two data types are used for this purpose- signed and unsigned. The signed data categories can include values that are positive as well as negative.

Contrarily, the unsigned data category consists of only positive integers. This exclusivity of the unsigned data category marks its distinct diversity from the signed category.

Signed integers use flag symbols to connote the negative integers. Unsigned data types do not use such flag symbols as all the integers included in this category are invariably positive.

This seminal difference between the two has to be cognized in order to refrain from using the two incorrectly. If the two data categories are used incorrectly or their usage is amalgamated in a way that affects the programming of the device, the computer usually issues a warning, notifying the user to rectify the misgiving.

References

  1. https://ieeexplore.ieee.org/abstract/document/6606625/
  2. https://link.springer.com/chapter/10.1007/978-3-540-28628-8_8
  3. https://www.cs.umn.edu/sites/cs.umn.edu/files/tech_reports/14-006.pdf