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Pointer parameters allow a function to modify the value in the calling function: create a pointer variable, which stores the address of the variable to be modified. Declare pointer parameters as parameters in the function declaration. When calling a function, pass the address of the variable as a parameter. Inside a function, use the dereference operator (*) to modify a pointer to a variable value.
Using pointer parameters to modify values in the calling function
Pointer parameters are a powerful technique that allow functions to modify the calling function Variables in functions.
The principle of pointers
A pointer is a variable that stores the address of another variable. You create a pointer by taking the address of a variable.
int age = 25; int *agePtr = &age;
Now, agePtr
contains the address of the age
variable.
Using pointer parameters
To use pointer parameters, declare the parameter as a pointer in the function declaration. For example:
void incrementAge(int *age) { *age += 1; }
When calling a function, pass the address of the variable as a parameter.
int age = 25; incrementAge(&age);
Practical Case
Let us use a simple example to show how to use pointer parameters to modify values in functions.
#include <stdio.h> void incrementAge(int *age) { *age += 1; } int main() { int age = 25; incrementAge(&age); printf("Age after increment: %d\n", age); return 0; }
In this example, the incrementAge
function receives the address of the variable age
using a pointer argument. Within the function, it uses the dereference operator (*
) to modify the value of age
.
Conclusion
Using pointer parameters is an effective way to modify the value of a variable in a calling function. This is useful in situations where you need to modify complex data structures or pass large data sets to functions.
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