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Immediately invoked function expressions can be used to avoid variable hoisting from within blocks, protecting against polluting the global environment and simultaneously allowing public access to methods while retaining privacy for variables defined within the function. In other words, it wraps functions and variables, keeping them out of the ...
Downcasting is useful when the type of the value referenced by the Parent variable is known and often is used when passing a value as a parameter. In the below example, the method objectToString takes an Object parameter which is assumed to be of type String.
Call by reference (or pass by reference) is an evaluation strategy where a parameter is bound to an implicit reference to the variable used as argument, rather than a copy of its value. This typically means that the function can modify (i.e., assign to ) the variable used as argument—something that will be seen by its caller.
Many dynamic languages, such as JavaScript, Lua, Python, Perl [1] [2] and PHP, allow a function object to be passed. CLI languages such as C# and VB.NET provide a type-safe encapsulating function reference known as delegate. Events and event handlers, as used in .NET languages, provide for callbacks.
For a simple type like a number these conventions are relatively clear. Passing ByRef allows the procedure to modify the passed variable whereas passing ByVal does not. For an object, semantics can confuse programmers since an object is always treated as a reference. Passing an object ByVal copies the reference; not the state of the object. The ...
The specification for pass-by-reference or pass-by-value would be made in the function declaration and/or definition. Parameters appear in procedure definitions; arguments appear in procedure calls. In the function definition f(x) = x*x the variable x is a parameter; in the function call f(2) the value 2 is the argument of the function. Loosely ...
The reference to the object is passed as a hidden argument, usually accessible from within the method as this. A parameter called by reference is syntactic sugar for technically passing a pointer as the parameter, but syntactically handling it as the variable itself, to avoid constant pointer de-referencing in the code inside the function.
The assembler takes a reference to the client, casts it to the setter interface that sets that dependency, and passes it to that dependency object which in turn passes a reference to itself back to the client. For interface injection to have value, the dependency must do something in addition to simply passing back a reference to itself.