When was null created?

It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler.

Why was null a mistake?

The problem with NULL is that it is a non-value value, a sentinel, a special case that was lumped in with everything else. Instead, we need an entity that contains information about (1) whether it contains a value and (2) the contained value, if it exists.

What is the point of null?

A NULL value is a special marker used in SQL to indicate that a data value does not exist in the database. In other words, it is just a placeholder to denote values that are missing or that we do not know. NULL can be confusing and cumbersome at first.

Why is it often said that the introduction of null is a billion dollar mistake?

The language could have been designed without it. Tony Hoare , the inventor of null (in ALGOL) calls it a “billion dollar mistake”: This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.

Who invented the concept of null?

Speaking at a software conference in 2009, Tony Hoare apologized for inventing the null reference: I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W).

5 Null Sightings in Minecraft that will leave you TERRIFIED! (Top Minecraft Countdown)

Is null really a mistake?

While undefined has been in existence since the creation of coding, null is the misguided invention of British computer scientist Tony Hoare (most famous for his Quicksort algorithm) in 1964, who coined his invention of null references as his “billion dollar mistake”.

Why is null true?

If a string-based field has null=True , that means it has two possible values for "no data": NULL , and the empty string. In most cases, it's redundant to have two possible values for "no data"; the Django convention is to use the empty string, not NULL .

What happens if you write to null?

The null device acts like a black hole. Anything written to it is discarded, and if you try to read from it you receive an end-of-file immediately.

Is null always 0?

The null pointer constant is always 0. The NULL macro may be defined by the implementation as a naked 0 , or a cast expression like (void *) 0 , or some other zero-valued integer expression (hence the "implementation defined" language in the standard).

Is null good or bad?

What is wrong with this method? It may return NULL instead of an object—that's what is wrong. NULL is a terrible practice in an object-oriented paradigm and should be avoided at all costs.

Why is it bad to return null?

It's very tempting to just return a null reference, but this could cause problems for the caller. If the caller(or callers), fails to do a null check, it could result in a NullPointerException being thrown if some value from the item object is used.

What is null in time?

time(NULL) returns the number of seconds elapsed since 00:00:00 hours, GMT (Greenwich Mean Time), January 1, 1970.

What is \0 in C?

'\0' is referred to as NULL character or NULL terminator It is the character equivalent of integer 0(zero) as it refers to nothing In C language it is generally used to mark an end of a string.

What is the symbol for nothing?

Null sign (∅), the empty set.

Is space a null character?

Typically, a null character is represented by a "space" or empty data set in applications such as a word processing database and is used for filling empty spaces and padding. In programming languages/context, a null character is represented by the escape sequence , and it marks the end of a character string.

Is it safe to delete null?

Yes it is safe. There's no harm in deleting a null pointer; it often reduces the number of tests at the tail of a function if the unallocated pointers are initialized to zero and then simply deleted. There are all sorts of nits that can be picked with the sample code, but the concept is (I hope) clear.

Is it OK to free null?

Calling free() on a NULL pointer

Sometimes it is convenient to allow a pointer that you call free on to point to a null location (an example is given below). Fortunately, that is perfectly fine to do. free() does absolutely nothing on a NULL pointer.

What is null in math?

In mathematical sets, the null set is a set that does not contain any values or elements. It is expressed as { } and denoted using the Greek letter ∅ (phi). A null set is also known as an empty set or void set. There is only one null set because, logically, there's only one way that a set can contain nothing.

Is null null false?

If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE.

Is null the same as false?

NULL is used to denote the null pointer constant, which evaluates to false in a boolean context. It really doesn't matter how it's specifically defined.

Does Java have null?

null is a reserved word (keyword) in Java for literal values. It is a literal similar to the true and false. In Java, null is a keyword much like the other keywords public, static or final. It is just a value that shows that the object is referring to nothing.

What the heck is null?

In most cases, NULL or nil means "no value" or "not applicable". Sometimes (like, when passed to a routine as an argument) it means "no explicit value". In SQL, it often means "not known".

Does null mean yes?

Null means having no value; in other words null is zero, like if you put so little sugar in your coffee that it's practically null. Null also means invalid, or having no binding force. From the Latin nullus, meaning "not any," poor, powerless null is not actually there at all.

Where does null come from?

English borrowed null from the Anglo-French nul, meaning "not any." That word, in turn, traces to the Latin word nullus, from ne-, meaning "not," and ullus, meaning "any." Null often pops up in legal and scientific contexts.

What is backslash 0?

The slashed zero glyph is often used to distinguish the digit "zero" ("0") from the Latin script letter "O" anywhere that the distinction needs emphasis, particularly in encoding systems, scientific and engineering applications, computer programming (such as software development), and telecommunications.