Functions and types of function in Cpp
Duration: 5 min
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The video is a lecture on functions in C++ programming, presented as a slide deck. It begins by defining a function as a block of code that executes when called, emphasizing their role in code reuse. The structure of a C++ function is explained as consisting of two parts: a declaration (specifying return type, name, and parameters) and a definition (the code body). An example function, `void myFunction()`, is shown to illustrate this. The lecture then categorizes functions into two types: User-Defined Functions, which are custom blocks of code created by the programmer to reduce complexity, and Library Functions, which are pre-built, built-in functions like `sqrt()`, `setw()`, and `strcat()` that are part of the compiler package and can be used directly. The final section of the video details the two primary methods for passing parameters to a function: Pass by Value, where a copy of the actual parameter is made, and changes do not affect the original; and Pass by Reference, where the actual and formal parameters refer to the same memory location, so changes made within the function are reflected in the original variable. The instructor uses on-screen text, diagrams, and handwritten annotations to explain these concepts.
Chapters
0:00 – 2:00 00:00-02:00
The video starts with a slide defining a function as a block of code that runs when called, used for performing actions and reusing code. It explains that a C++ function has two parts: a declaration and a definition. The declaration includes the return type, function name, and parameters (if any), while the definition contains the body of code to be executed. An example is provided: `void myFunction() { // declaration } // the body of the function (definition)`. The instructor highlights the text 'when it is called' and writes 'void myFunction()' on the screen to illustrate the concept.
2:00 – 4:36 02:00-04:36
The lecture transitions to a diagram titled 'Types of Functions', which branches into 'User Defined Function' and 'Library Function'. The instructor explains that user-defined functions are custom blocks of code created by the user to reduce complexity, while library functions are built-in functions like `sqrt()`, `setw()`, and `strcat()` that are part of the compiler package and can be used directly. The next slide introduces the two ways to pass parameters: 'Pass by Value' and 'Pass by Reference'. For 'Pass by Value', the instructor explains that values are copied, and changes in the function do not affect the original parameters. For 'Pass by Reference', the instructor explains that both actual and formal parameters refer to the same memory location, so changes are reflected in the original. The instructor draws diagrams to illustrate these concepts, showing separate memory locations for pass by value and shared locations for pass by reference.
The video provides a comprehensive overview of C++ functions, starting with a fundamental definition and structure. It systematically progresses from the basic concept of a function to its two main components: declaration and definition, using a clear example. The lesson then expands the scope by categorizing functions into user-defined and library types, highlighting the practical difference between creating custom code and using pre-existing, built-in functions. The final segment focuses on a critical programming concept—parameter passing—by contrasting the two most common methods, pass by value and pass by reference, using both textual explanation and visual diagrams to clarify the memory implications of each approach. This structured progression builds a solid foundation for understanding how to effectively use and design functions in C++.