Forum: english.stackexchange.com
Tags: <synonyms>
Title: Is there a real difference between "null" and "zero"?
Question: Are  zero  and  null  perfect synonyms?

Answers:
sents: text: 'null' is qualitative, representing the absence of quantity.
text: Closer to the word 'void' than the number 'zero'.
text: Example: he reduced it to nil.
text: 'zero' is quantitative.
text: Example: he got zero on his exam.
answer_details: author: english.stackexchange.com/users/1114/Wadih M.
score: 21
sents: text: No, they are not the same.
text: In an everyday language context, 'null' can mean that something is meaningless, as in: The agreement became null when Sam failed to fulfill his side.
text: In a programming/data context (though I still think this is a language question, rather than a programming question),
text: 'null' can mean the absence of information.
text: If you are wondering how many apples there are, 'null' means 'I don't know'.
text: 'Zero' means that you know that there aren't any apples.
text: Zero always refers to a quantity.
answer_details: author: english.stackexchange.com/users/433/pkaeding
score: 7
sents: text: Is there a difference between a cheque(check) with $0.00 and a NULL(VOID) check?
text: Yes.
text: A $0.00 cheque will put exactly $0.00 into your bank account.
text: A check with VOID written on it will not be processed.
text: The difference may be subtle, but there is a difference.
text: 0 represents an integer in the set of all integers (called the set Z in mathematics)NULL is not an integer, and it could represent the absence of things that aren't even numbers.
text: A NULL and VOID Check for example.
text: A NULL Marriage.
text: A NULL Agreement
answer_details: author: english.stackexchange.com/users/134/OneProton
score: 7
sents: text: null and zero are used in many contexts where they have different meanings.
text: In math you can have a set with no items in it (a null set) or you can have a set with a zero in it ({ 0 }) which are not the same.
text: In programming some languages make null the same as zero (C++) but some don't (Java).
text: In databases a record might have a null value in one field or it might have a zero and these are not the same.
text: Zero is can be used to indicate a counted quantity whereas null cannot.
answer_details: author: english.stackexchange.com/users/380/Mr. Shiny and New 安宇
score: 7
sents: text: It's not just null and zero too.
text: What about "nothing","naugt","none" etc.
text: Zero is usually a noun.
text: Zero is a number.
text: Zero can refer to the symbol "0".
text: Null is usually an adjective (Null set, Null argument, Null pointer, *a nullity).
text: Null is a not a number, usually has a different symbol each time.
text: Programmers are forced to make these distinctions all the time (although, 'null' is often modelled as the number 0).
text: Although it is important in programming, the distinction is more to do with logic and mathematics.
text: They do have quite different roles in language although I guess in a few cases they are the same. History of Zero
answer_details: author: english.stackexchange.com/users/1318/Lucas
score: 2
sents: text: The words have very different meanings.
text: In math, I can do an equation, such as subtract two numbers, and get zero.
text: If I don't answer the question, it could be considered null.
text: If the question were an elementary test, zero could be the correct answer, worth points, whereas not answering the question does not result in a correct answer.
text: So, one can indicate that a computation has been done, the other that it has not been done.
answer_details: author: english.stackexchange.com/users/728/thursdaysgeek
score: 2
sents: text: "Zero" is a number, an integer between -1 and 1.
text: It is a physical quantity representing no countable number of an object.
text: "Null" is a concept of irrelevance or undefined state.
text: For example, an agreement might become "null and void" when it is no longer applicable or enforceable, or a computer data structure pointer with no instantiation associated with it might be considered "null".
text: The confusion comes in the representation of a computer NULL in execution.
text: Typically, the NULL is represented as a 0 in the memory or code.
text: But that is just a convention.
text: It's like saying "I am Spoxjox".
text: Well, no, I am not Spoxjox.
text: I am represented by the "name" or "tag" or "handle" of "Spoxjox", but I am a human being, not a sequence of letters on a discussion board.
text: Similarly, the concept of NULL might be represented by a zero (0), but it is not the same as the number zero.
answer_details: author: english.stackexchange.com/users/17589/Spoxjox
score: 0
sents: text: No.
text: Zero is a number.
text: Zero is also a place where a mathematical function achieves an output value of zero.
text: Null has a wide variety of uses.
text: Here are a few: null set - a set devoid of elements null contract - unenforceable contract The Java computer language uses null as a "graveyard" object that holds no value
answer_details: author: english.stackexchange.com/users/9859/ncmathsadist
score: 0
sents: text: "Nula" is the word for "0" in Hungarian and other European languages.
text: "Null" means "void of legal force" ...
text: that's essentially "invalid".
text: It's an adjective, as has been mentioned.
text: I'm not a programmer, so
text: maybe that's why I don't equate the two at all.
text: Compare "Are you Rachel?"
text: with "Are you tired?"
answer_details: author: english.stackexchange.com/users/17687/anastasia
score: 0

Summary of the answers:
No, these are not perfect synonyms. The difference may be subtle, but there is a difference. Zero always refers to a quantity whereas "null" is a concept of irrelevance or undefined state. Null is not a number and represents the absence of quantity.
Null  and  zero  are not the same and they are used in many contexts where they have different meanings.  Null' is qualitative, representing the absence of quantity. Null is also used as an adjective (Null set, Null argument, Null pointer, *a nullity). S2: "Null" is a concept of irrelevance or undefined state. Zero is a noun and always refers to a quantity and can be used to indicate a counted quantity whereas null cannot.
The words have different meanings.  In math you can have a set with no items in it (a null set) or you can have a set with a zero in it ({ 0 }) which are not the same.  In programming some languages make null the same as zero (C++) but some don't (Java).  In databases a record might have a null value in one field or it might have a zero and these are not the same. Zero can be used to indicate a counted quantity whereas null cannot.
It is generally agreed that these are not perfect synonyms. There are many instances in which "zero" is a value whereas "null" refers to the absence of a value.