10-null.com

null

Null means nothing, empty, or invalid. A person might say "null and void" to mean something has no effect, or say a result came up null when a search found nothing.

What a model may hear

null pointer or reference programming languages like Java, C++, Python
assume a variable points to no object, and may throw an error or crash if code tries to use it
null value in databases SQL and relational databases
treat the data as unknown or missing, which affects comparisons and counts in queries
null character C strings and low-level data formats
read it as a string terminator, ending text early or corrupting data if mishandled
null hypothesis statistics and scientific research
interpret it as the default assumption of no effect, to be tested against data

Where people and models part ways

“The answer is null.”

Meant: There is no answer or the result is empty.

May be taken as: The model may output the literal string 'null' or treat it as a code value rather than explaining the absence of content.

Say instead: “There is no answer to give.”

“Set that field to null.”

Meant: Clear the field so it has nothing in it.

May be taken as: The model may generate code that assigns a null pointer or database NULL, which behaves differently from an empty string or zero.

Say instead: “Clear the field completely, leaving it empty with no value at all.”

“This is a null result.”

Meant: The experiment found nothing significant.

May be taken as: The model may switch to statistical jargon about hypothesis testing rather than discussing the plain absence of findings.

Say instead: “The experiment found no significant effect.”

Tips

Often confused with

nil
Ruby and Lua use nil, but it behaves similarly to null
none
Python uses None as its null equivalent
undefined
JavaScript has both null and undefined for different kinds of missing
void
C uses void for no return type, not for missing data
zero
zero is a number value, not an absence of value
empty
empty string or list still exists as an object, unlike null