How do you return a value from a Delphi function?
How do you return a value from a Delphi function?
Only one value can be returned from a function. However, using the out or var keyword before a parameter allows the parameter to be treated as variable to contain return values. In both cases, the returned value is passed by assigning to the Result pseudo variable.
What is a parameter 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.
How do you call a method in Delphi?
You can make the call using the declared name of the routine (with or without qualifiers) or using a procedural variable that points to the routine. In either case, if the routine is declared with parameters, your call to it must pass parameters that correspond in order and type to the parameter list of the routine.
What is Stdcall in Delphi?
The stdcall directive uses the Windows standard calling convention: arguments are pushed onto the stack, starting with the rightmost argument. The subroutine is responsible for popping the arguments from the stack.
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);
What are functions 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 I get a substring in Delphi?
You can use the Copy function to extract a sequence of characters from a string: cSerial. Text := Copy(Result, 2, 3); Note that the third parameter is the number of characters to extract, not the index of the last character.
How do you exit a loop in Delphi?
To stop running a loop, use the break command. Exit is also useful to leave an entire function, especially when you have multiple nested loops to escape. As a last resort, you can use goto to jump out of several nested loops and continue running in the same function.
How do I create a class in Delphi?
Defining New Classes (Delphi)
- In the IDE, start with a project open and choose File > New > Unit to create a new unit where you can define the new class.
- Add the uses clause and type section to the interface section.
- In the type section, write the class declaration.
How do you count characters in Delphi?
Use below function. function CountCharInString(str: string; SearchChar: char): integer; // DESC: Returns the number of times a character occurs in a string. // PARAM: str – the string. // PARAM: SearchChar – the character to count the occurrences of. // RETURNS: The number of times SearchChar occurs in str.