What are parameters in Delphi?
Parameters are special kind of variables declared in a subroutine that are used to input some value into that subroutine. And the values that we pass in a function call is called as Arguments. in Delphi we can declare functions/procedures with parameters like following. Example of a Function declaration.
What is overload in Delphi?
The overload directive tells Delphi that you will declare another subroutine with the same name but with different parameters.
How do you pass by reference in Delphi?
In Delphi to pass by reference you explicitly add the var keyword: procedure myFunc(var mytext:String); This means that myFunc can modify the contents of the string and have the caller see the changes.
What is function in Delphi?
In Delphi, there are generally two types of subroutines: a ​function and a procedure. The usual difference between a function and a procedure is that a function can return a value, and a procedure generally will not do so. A function is normally called as a part of an expression.
How do you exit a function in Delphi?
In Delphi, you can Exit a function and give it a return value which is very similar to the return keyword in C/C++/Java/C# etc. Exit(1);
How do I use pointers in Delphi?
The syntax to declare a pointer data type uses a caret (^). In the above code, iValue is an integer type variable and pIntValue is an integer type pointer. Since a pointer is nothing more than an address in memory, we must assign to it the location (address) of the value stored in the iValue integer variable.
What does cdecl stand for?
C declaration
cdecl. The cdecl (which stands for C declaration) is a calling convention that originates from Microsoft’s compiler for the C programming language and is used by many C compilers for the x86 architecture. In cdecl, subroutine arguments are passed on the stack.
How do I stop Pascal program?
Exit exits the current subroutine, and returns control to the calling routine. If invoked in the main program routine, exit stops the program. The optional argument X allows to specify a return value, in the case Exit is invoked in a function. The function result will then be equal to X .
How do you end a program in Pascal?
Every block in Pascal is enclosed within a begin statement and an end statement. However, the end statement indicating the end of the main program is followed by a full stop (.)
What are pointer types?
There are majorly four types of pointers, they are: Null Pointer. Void Pointer. Wild Pointer. Dangling Pointer.
Which of these variable types matches a pointer?
Important point to note is: The data type of pointer and the variable must match, an int pointer can hold the address of int variable, similarly a pointer declared with float data type can hold the address of a float variable. In the example below, the pointer and the variable both are of int type.
How do you declare a constant array in Delphi?
Example Declaration of Three Constant Arrays Days[1] returns the Mon string. CursorMode is an array of two elements, whereby declaration CursorMode[false] = crHourGlass and CursorMode = crSQLWait. “cr*” constants can be used to change the current screen cursor. Items defines an array of three TShopItem records.
How to give a default value for the parameter of a function?
In order to simplify some statements, we can give a default value for the parameter of a function or procedure, and we can call the routine with or without the parameter, making it optional. To provide a default value, end the parameter declaration with the equal (=) symbol followed by a constant expression. For example, given the declaration.
What are the programming languages used in Delphi?
He is also proficient in XML, DHTML, and JavaScript. Functions and procedures are an important part of the Delphi language.
What is a default parameter in C++?
Default parameters are a great way for programmers to write less (and probably much clearer) code. Default arguments in declarations should be used to denote – indeed – default values and default behaviour, where we don’t even need to specify the actual values.
How to set default parameter value in DoSomething method?
Default parameter value The syntax for this is as follows: procedure DoSomething(Param: string = ”); You can call the method like this: DoSomething(); DoSomething(”); Both of the above behave in the same way.