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In object-oriented computer programming, a null object is an object with no referenced value or with defined neutral (null) behavior.The null object design pattern, which describes the uses of such objects and their behavior (or lack thereof), was first published as "Void Value" [1] and later in the Pattern Languages of Program Design book series as "Null Object".
In computer programming, lazy initialization is the tactic of delaying the creation of an object, the calculation of a value, or some other expensive process until the first time it is needed.
Nullable types are a feature of some programming languages which allow a value to be set to the special value NULL instead of the usual possible values of the data type.In statically typed languages, a nullable type is an option type, [citation needed] while in dynamically typed languages (where values have types, but variables do not), equivalent behavior is provided by having a single null ...
Programming languages use different literals for the null pointer. In Python, for example, a null value is called None. In Java and C#, the literal null is provided as a literal for reference types. In Pascal and Swift, a null pointer is called nil. In Eiffel, it is called a void reference.
In computer programming, a null-terminated string is a character string stored as an array containing the characters and terminated with a null character (a character with an internal value of zero, called "NUL" in this article, not same as the glyph zero).
In all modern character sets, the null character has a code point value of zero. In most encodings, this is translated to a single code unit with a zero value. For instance, in UTF-8 it is a single zero byte. However, in Modified UTF-8 the null character is encoded as two bytes: 0xC0,0x80. This allows the byte with the value of zero, which is ...
Perl autovivification can be contrasted against languages such as Python, PHP, Ruby, and many of the C style languages, where dereferencing null or undefined values is not generally permitted. [ a ] It can be compared to the HTML standard's "named access on the window object" [ 2 ] which results in corresponding globally scoped variables being ...
The single copy of each string is called its intern and is typically looked up by a method of the string class, for example String.intern() [2] in Java. All compile-time constant strings in Java are automatically interned using this method. [3] String interning is supported by some modern object-oriented programming languages, including Java ...