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Safe Navigation Operator
In object-oriented programming, the safe navigation operator (also known as optional chaining operator, safe call operator, null-conditional operator, null-propagation operator) is a binary operator that returns null if its first argument is null; otherwise it performs a dereferencing operation as specified by the second argument (typically an object member access, array index, or lambda invocation). It is used to avoid sequential explicit null checks and assignments and replace them with method/property chaining. In programming languages where the navigation operator (e.g. ".") leads to an error if applied to a null object, the safe navigation operator stops the evaluation of a method/field chain and returns null as the value of the chain expression. It was first used by Groovy 1.0 in 2007 and is currently supported in languages such as C#, Swift, TypeScript, Ruby, Kotlin, Rust, JavaScript, and others. There is currently no common naming convention for this operator, but safe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object-oriented Programming
Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and implemented in code). In OOP, computer programs are designed by making them out of objects that interact with one another. Many of the most widely used programming languages (such as C++, Java, and Python) support object-oriented programming to a greater or lesser degree, typically as part of multiple paradigms in combination with others such as imperative programming and declarative programming. Significant object-oriented languages include Ada, ActionScript, C++, Common Lisp, C#, Dart, Eiffel, Fortran 2003, Haxe, Java, JavaScript, Kotlin, Logo, MATLAB, Objective-C, Object Pascal, Perl, PHP, Python, R, Raku, Ruby, Scala, SIMSCRIPT, Simula, Smalltalk, Swift, Vala and Visual Basic.NET. History The idea of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apex (programming Language)
Salesforce, Inc. is an American Cloud computing, cloud-based software company headquartered in San Francisco, California. It provides applications focused on sales, customer service, marketing automation, e-commerce, analytics, artificial intelligence, and application development. Founded by former Oracle Corporation, Oracle executive Marc Benioff in March 1999, Salesforce grew quickly, making its initial public offering in 2004. As of September 2022, Salesforce is the list of public corporations by market capitalization, 61st largest company in the world by market cap with a value of nearly US$153 billion. It became the world's largest enterprise applications firm in 2022. Salesforce ranked 491st on the 2023 edition of the Fortune 500, ''Fortune'' 500, making $31.352 billion in revenue. Since 2020, Salesforce has also been a component of the Dow Jones Industrial Average. History Salesforce was founded on March 8, 1999 by former Oracle Corporation, Oracle executive Marc Beniof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conditional Constructs
In computer science, conditionals (that is, conditional statements, conditional expressions and conditional constructs) are programming language constructs that perform different computations or actions or return different values depending on the value of a Boolean expression, called a ''condition''. Conditionals are typically implemented by selectively executing instructions. Although dynamic dispatch is not usually classified as a conditional construct, it is another way to select between alternatives at runtime. Terminology Conditional statements are imperative constructs executed for side-effect, while conditional expressions return values. Many programming languages (such as C) have distinct conditional statements and conditional expressions. Although in pure functional programming, conditional expressions do not have side-effects, many languages with conditional expressions (such as Lisp) support conditional side-effects. If–then(–else) The if–then or if� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operators (programming)
Operator may refer to: Mathematics * A symbol indicating a mathematical operation * Logical operator or logical connective in mathematical logic * Operator (mathematics), mapping that acts on elements of a space to produce elements of another space, e.g.: ** Linear operator ** Differential operator ** Integral operator (other) ** Operational calculus Computers * Computer operator, an occupation * Operator (computer programming), a type of computer program function * Operator (extension), an extension for the Firefox web browser, for reading microformats * Operator pattern, a provisioning automation and auto-scaling strategy for Kubernetes * Ableton Operator, a software synthesizer developed by Ableton Science * Operator (biology), a segment of DNA regulating the activity of genes * Operator (linguistics), a special category including wh- interrogatives * Operator (physics), mathematical operators in quantum physics Music * Operator (band), an American hard rock ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Null Coalescing Operator
The null coalescing operator is a binary operator that is part of the syntax for a basic conditional expression in several programming languages, such as (in alphabetical order): C# since version 2.0, Dart since version 1.12.0, PHP since version 7.0.0, Perl since version 5.10 as ''logical defined-or'', PowerShell since 7.0.0, and Swift as ''nil-coalescing operator''. It is most commonly written as x ?? y, but varies across programming languages. While its behavior differs between implementations, the null coalescing operator generally returns the result of its left-most operand if it exists and is not null, and otherwise returns the right-most operand. This behavior allows a default value to be defined for cases where a more specific value is not available. Like the binary Elvis operator, usually written as x ?: y, the null coalescing operator is a short-circuiting operator and thus does not evaluate the second operand if its value is not used, which is significant if its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nullable Type
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, while in dynamically typed languages (where values have types, but variables do not), equivalent behavior is provided by having a single null value. NULL is frequently used to represent a missing value or invalid value, such as from a function that failed to return or a missing field in a database, as in NULL in SQL. In other words, NULL is undefined. Primitive types such as integers and Booleans cannot generally be null, but the corresponding nullable types (nullable integer and nullable Boolean, respectively) can also assume the NULL value. This can be represented in ternary logic as FALSE, NULL, TRUE as in three-valued logic. Example An integer variable may represent integers, but 0 (zero) is a special case because 0 in many programming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Value Type
In certain computer programming languages, data types are classified as either value types or reference types, where reference types are always implicitly accessed via references, whereas value type variables directly contain the values themselves. Properties of value types and reference types Even among languages that have this distinction, the exact properties of value and reference types vary from language to language, but typical properties include: * Primitive data types, such as Booleans, fixed-size integers, floating-point values, and characters, are value types. * Objects, in the sense of object-oriented programming, belong to reference types. * Assigning to a variable of reference type simply copies the reference, whereas assigning to a variable of value type copies the value. This applies to all kinds of variables, including local variables, fields of objects, and array elements. Likewise when calling a function: parameters of reference type are copies of the reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elvis Operator
In certain computer programming languages, the Elvis operator, often written ?:, is a binary operator that evaluates its first operand and returns it if its value is ''logically true'' (according to a language-dependent convention, in other words, a '' truthy'' value), and otherwise evaluates and returns its second operand. The second operand is only evaluated if it is to be returned ( short-circuit evaluation). The notation of the Elvis operator was inspired by the ternary conditional operator, ? :, since the Elvis operator expression A ?: B is approximately equivalent to the ternary conditional expression A ? A : B. The name "Elvis operator" refers to the fact that when its common notation, ?:, is viewed sideways, it resembles an emoticon of Elvis Presley with his signature hairstyle. A similar operator is the null coalescing operator, where the boolean truth(iness) check is replaced with a check for non-null instead. This is usually written ??, and can be seen in languages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salesforce
Salesforce, Inc. is an American cloud-based software company headquartered in San Francisco, California. It provides applications focused on sales, customer service, marketing automation, e-commerce, analytics, artificial intelligence, and application development. Founded by former Oracle executive Marc Benioff in March 1999, Salesforce grew quickly, making its initial public offering in 2004. As of September 2022, Salesforce is the 61st largest company in the world by market cap with a value of nearly US$153 billion. It became the world's largest enterprise applications firm in 2022. Salesforce ranked 491st on the 2023 edition of the ''Fortune'' 500, making $31.352 billion in revenue. Since 2020, Salesforce has also been a component of the Dow Jones Industrial Average. History Salesforce was founded on March 8, 1999 by former Oracle executive Marc Benioff, together with Parker Harris, Dave Moellenhoff, and Frank Dominguez as a software-as-a-service (SaaS) company. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Null Coalescing Operator
The null coalescing operator is a binary operator that is part of the syntax for a basic conditional expression in several programming languages, such as (in alphabetical order): C# since version 2.0, Dart since version 1.12.0, PHP since version 7.0.0, Perl since version 5.10 as ''logical defined-or'', PowerShell since 7.0.0, and Swift as ''nil-coalescing operator''. It is most commonly written as x ?? y, but varies across programming languages. While its behavior differs between implementations, the null coalescing operator generally returns the result of its left-most operand if it exists and is not null, and otherwise returns the right-most operand. This behavior allows a default value to be defined for cases where a more specific value is not available. Like the binary Elvis operator, usually written as x ?: y, the null coalescing operator is a short-circuiting operator and thus does not evaluate the second operand if its value is not used, which is significant if its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
