Expressions in C#
A combination of operands (such Variables, literals, or method calls) and Operators that can be evaluated to a single value is called an expression in C#. Expressions are just bits of code that, when processed, produce a value, object, method, or namespace. They are regarded as a C# program’s fundamental building components.
Components and Structure of Expressions
Expression Structure and Components Expressions do not always need an operator, but they must have at least one operand. Simple components or intricate combinations can be among them.
Typical elements of expressions consist of:
Constants or Literals: A numeric constant, for instance, is 10,000 in the sentence if income >= 10,000. "Hello World" and "5" are also literal values.
Variable Names: For example, if income >= 10,000. The expression makes use of the variable’s value after retrieving it.
Operations: On operands are carried out by operators such as +, -, *, /, ==, >=, and?:.
Method Invocations: Calls to functions with a value return. For instance, the GetAge function is called by GetAge(dateOfBirth). It is not possible to utilize methods that return void in place of a value in an expression.
Parenthesized Expressions: The first expressions evaluated are those included in parenthesis.
Member Access: The dot (.) operator is used to access an object’s fields or properties, such as DateTime.UtcNow.
Array Element Access: Use square brackets [] to access array elements, such as letters.
Postfix/Prefix Increment/Decrement: Operators such as ++ and --.
new Operator: Utilized to create objects.
typeof Operator: Utilized to obtain the System.Type for atype object.
sizeof Operator : To obtain the size of compile-time known types in bytes, use the sizeof operator.
checked/unchecked Expressions: Verified or not Words Control overflow checks of arithmetic operations with this tool.
Types of Expressions in C#
Types and Groupings of Expressions The functions that C# expressions carry out can be used to categorise them:
Primary Expressions: Put expressions, method calls, variable names, and literals in parenthesis.
Unary Expressions: Expressions That Are Unary Involve a single operand, like prefix increment (++), prefix decrement (–), logical NOT (!), one’s complement (~), unary plus (+), or unary minus (-).
Arithmetic Expressions: Execute mathematical operations (a * b, a + b, etc.).
String Concatenation Expressions: Utilize the + operator to join strings.
Relational Expressions: Utilize comparison operators (<, >, <=, >=, ==,!=) to determine whether two values are related, yielding TRUE or FALSE.
Logical Expressions: Multiple criteria can be combined using logical operators (&&, ||,!, ^).
Conditional Expressions: To return one of two values depending on a Boolean condition, use the ternary operator (?:).
Assignment Expressions: To assign a value to a variable, use operators such as =, +=, -=, and so on.
Type Conversion Expressions: Convert data from one type to another via casting or by utilising operators like as or is.
Advanced Expression Types
Interpolated String Expressions: More understandable than composite formatting, interpolated string expressions (introduced in C# 6.0) enable embedding expression results directly into string literals prefixed with $.
Lambda Expressions: C# 3.0 introduced lambda expressions, which are used to build anonymous functions. The parameter list is separated from the function body using the => (lambda) operator. Statement lambdas (block statement body) or expression lambdas (single expression body) are two possible types. They serve as a shorthand for delegate initialisation and are frequently used with LINQ queries.
throw Expressions: The usage of throw expressions in expression-bodied members and other expression contexts, which were first introduced in C# 7.0, streamlines error handling logic.
Expression-Bodied Function Members: Expression-Bodied Members of the Function Allow the lambda operator => to specify the body of methods, properties, indexers, constructors, and finalisers as a single expression for more compact code (introduced in C# 6.0 and enhanced in C# 7.0).
Expression Trees: Code should be represented as a tree-like data structure with expressions at each node. They give lambda expressions an in-memory representation, enabling dynamic code execution and modification.