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Questions and Answers
What does a pointer in C contain?
What does a pointer in C contain?
What is the size of a pointer in C?
What is the size of a pointer in C?
What happens if a pointer is dereferenced without being assigned a valid memory address?
What happens if a pointer is dereferenced without being assigned a valid memory address?
In call by value, what happens to the value of the actual parameters?
In call by value, what happens to the value of the actual parameters?
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What is the main difference between call by value and call by reference in C?
What is the main difference between call by value and call by reference in C?
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What is the role of formal parameters in a function call?
What is the role of formal parameters in a function call?
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What happens to the value inside the function in call by value method?
What happens to the value inside the function in call by value method?
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What is the outcome of the example function 'square' in the given code?
What is the outcome of the example function 'square' in the given code?
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Study Notes
Pointers in C
- A pointer in C contains the memory address of a variable.
- It enables dynamic memory allocation and manipulation of variable addresses directly.
- Pointers can point to any data type, including arrays and functions.
Size of a Pointer
- The size of a pointer in C is typically 4 bytes on a 32-bit system and 8 bytes on a 64-bit system.
- Size may vary depending on the architecture and data type it points to.
Dereferencing Invalid Pointers
- Dereferencing a pointer without a valid memory address results in undefined behavior.
- This can lead to segmentation faults or access violations.
Call by Value
- In call by value, the actual parameter’s value is copied into the function's formal parameter.
- Changes made to the formal parameter do not affect the actual parameter outside the function.
Call by Value vs. Call by Reference
- Call by value passes a copy of a variable, while call by reference passes a reference (or address) to the actual variable.
- Changes to formal parameters in call by reference affect the actual parameters, allowing for direct manipulation of the original data.
Role of Formal Parameters
- Formal parameters act as placeholders in function definitions that receive values of actual parameters during function calls.
- They define the types of inputs that a function can accept.
Value Inside Function (Call by Value)
- Inside a function that uses call by value, the value of the formal parameter is local and separate from the actual parameter.
- Modifications to the formal parameter do not alter the actual parameter outside the function.
Example Function 'Square'
- The example function 'square' takes an integer input and returns its square.
- It showcases the use of call by value, where the original variable remains unchanged after the function call.
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Description
Test your knowledge of pointers in C with this quiz. Explore what a pointer in C contains, its size, and the consequences of dereferencing a pointer without a valid memory address.
