Concept
Undefined behavior
Related concepts (20)
Rust (programming language)
Rust is a multi-paradigm, general-purpose programming language that emphasizes performance, type safety, and concurrency. It enforces memory safety—ensuring that all references point to valid memory—without requiring the use of a garbage collector or reference counting present in other memory-safe languages. To simultaneously enforce memory safety and prevent data races, its "borrow checker" tracks the object lifetime of all references in a program during compilation.
Cyclone (programming language)
The Cyclone programming language is intended to be a safe dialect of the C language. Cyclone is designed to avoid buffer overflows and other vulnerabilities that are possible in C programs, without losing the power and convenience of C as a tool for system programming. Cyclone development was started as a joint project of AT&T Labs Research and Greg Morrisett's group at Cornell University in 2001. Version 1.0 was released on May 8, 2006. Cyclone attempts to avoid some of the common pitfalls of C, while still maintaining its look and performance.
Null pointer
In computing, a null pointer or null reference is a value saved for indicating that the pointer or reference does not refer to a valid object. Programs routinely use null pointers to represent conditions such as the end of a list of unknown length or the failure to perform some action; this use of null pointers can be compared to nullable types and to the Nothing value in an option type. A null pointer should not be confused with an uninitialized pointer: a null pointer is guaranteed to compare unequal to any pointer that points to a valid object.
Variable (computer science)
In computer programming, a variable is an abstract storage location paired with an associated symbolic name, which contains some known or unknown quantity of data or object referred to as a value; or in simpler terms, a variable is a named container for a particular set of bits or type of data (like integer, float, string etc...). A variable can eventually be associated with or identified by a memory address. The variable name is the usual way to reference the stored value, in addition to referring to the variable itself, depending on the context.
Uninitialized variable
In computing, an uninitialized variable is a variable that is declared but is not set to a definite known value before it is used. It will have some value, but not a predictable one. As such, it is a programming error and a common source of bugs in software. A common assumption made by novice programmers is that all variables are set to a known value, such as zero, when they are declared. While this is true for many languages, it is not true for all of them, and so the potential for error is there.
Syntax (programming languages)
In computer science, the syntax of a computer language is the rules that define the combinations of symbols that are considered to be correctly structured statements or expressions in that language. This applies both to programming languages, where the document represents source code, and to markup languages, where the document represents data. The syntax of a language defines its surface form. Text-based computer languages are based on sequences of characters, while visual programming languages are based on the spatial layout and connections between symbols (which may be textual or graphical).
Side effect (computer science)
In computer science, an operation, function or expression is said to have a side effect if it modifies some state variable value(s) outside its local environment, which is to say if it has any observable effect other than its primary effect of returning a value to the invoker of the operation. Example side effects include modifying a non-local variable, modifying a static local variable, modifying a mutable argument passed by reference, performing I/O or calling other functions with side-effects.
Segmentation fault
In computing, a segmentation fault (often shortened to segfault) or access violation is a fault, or failure condition, raised by hardware with memory protection, notifying an operating system (OS) the software has attempted to access a restricted area of memory (a memory access violation). On standard x86 computers, this is a form of general protection fault. The operating system kernel will, in response, usually perform some corrective action, generally passing the fault on to the offending process by sending the process a signal.
Pointer (computer programming)
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer references a location in memory, and obtaining the value stored at that location is known as dereferencing the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page.
Swift (programming language)
Swift is a high-level general-purpose, multi-paradigm, compiled programming language developed by Apple Inc. and the open-source community. First released in June 2014, Swift was developed as a replacement for Apple's earlier programming language Objective-C, as Objective-C had been largely unchanged since the early 1980s and lacked modern language features. Swift works with Apple's Cocoa and Cocoa Touch frameworks, and a key aspect of Swift's design was the ability to interoperate with the huge body of existing Objective-C code developed for Apple products over the previous decades.