Passing an Array to a Function (ICT Programming)
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Arrays passed to functions are passed by reference, not by value. When an array is passed to a function, the function receives the address of the first element. Any modifications made to the array elements inside the function are reflected in the original array in memory. Arrays do not need an ampersand (&) when passed to a function. The function prototype only needs to specify the array name without brackets to indicate an array parameter.
![• When passing an array to a function, we need to tell the
compiler what the type of the array is and give it a
variable name, similar to an array declaration
float a[] parameter
• We need to specify the name of the array without any
brackets
int myArray[24];
myFunction(myArray,24);
-Arrays passed call-by-reference
-Name of array is address of first element
-Function knows where the array is stored(Modifies
original memory locations)](https://image.slidesharecdn.com/passinganarraytoafunction-140317053722-phpapp02/85/Passing-an-Array-to-a-Function-ICT-Programming-2-320.jpg)
![ARRAYS ARE ALWAYS PASSED BY REFERENCE
• Arrays are automatically passed by reference. Do not use &.
• If the function modifies the array, it is also modified in the
calling environment
void Zero(int arr[], int N)
{
for (int k=0; k<N; k++)
arr[k]=0;
Function prototype:
void modifyArray( int b[], int arraySize );
-Parameter names optional in prototype
int b[] could be written int []
int arraySize could be simply int](https://image.slidesharecdn.com/passinganarraytoafunction-140317053722-phpapp02/85/Passing-an-Array-to-a-Function-ICT-Programming-3-320.jpg)
![/*Example Number 1*/
#include <iostream.h>
int Display(intint data[],int N)
{ int k;
cout<<“Array contains”<<endl;
for (k=0; k<N; k++)
cout<<data[k]<<“ “;
cout<<endl;
}
int main()
{
int a[4] = { 11, 33, 55, 77 };
Display(a, 4);
}
An int array parameter
of unknown size
Size of the array
The array argument](https://image.slidesharecdn.com/passinganarraytoafunction-140317053722-phpapp02/85/Passing-an-Array-to-a-Function-ICT-Programming-4-320.jpg)
![/*Example Number 2*/
#include <iostream.h>
int sum(int data[], int n);
void main()
{
int a[] = { 11, 33, 55, 77 };
int size = sizeof(a)/sizeof(int);
cout << "sum(a,size) = " << sum(a,size) << endl;
}
int sum(int data[], int n)
{
int sum=0;
for (int i=0; i<n;i++)
sum += data[i];
return sum;
}
The array argument
An int parameter of
unkown size
Size of the array](https://image.slidesharecdn.com/passinganarraytoafunction-140317053722-phpapp02/85/Passing-an-Array-to-a-Function-ICT-Programming-5-320.jpg)
Passing an Array to a Function (ICT Programming)
- 1. PASSING AN ARRAY TO A FUNCTION
- 2. • When passing an array to a function, we need to tell the compiler what the type of the array is and give it a variable name, similar to an array declaration float a[] parameter • We need to specify the name of the array without any brackets int myArray[24]; myFunction(myArray,24); -Arrays passed call-by-reference -Name of array is address of first element -Function knows where the array is stored(Modifies original memory locations)
- 3. ARRAYS ARE ALWAYS PASSED BY REFERENCE • Arrays are automatically passed by reference. Do not use &. • If the function modifies the array, it is also modified in the calling environment void Zero(int arr[], int N) { for (int k=0; k<N; k++) arr[k]=0; Function prototype: void modifyArray( int b[], int arraySize ); -Parameter names optional in prototype int b[] could be written int [] int arraySize could be simply int
- 4. /*Example Number 1*/ #include <iostream.h> int Display(intint data[],int N) { int k; cout<<“Array contains”<<endl; for (k=0; k<N; k++) cout<<data[k]<<“ “; cout<<endl; } int main() { int a[4] = { 11, 33, 55, 77 }; Display(a, 4); } An int array parameter of unknown size Size of the array The array argument
- 5. /*Example Number 2*/ #include <iostream.h> int sum(int data[], int n); void main() { int a[] = { 11, 33, 55, 77 }; int size = sizeof(a)/sizeof(int); cout << "sum(a,size) = " << sum(a,size) << endl; } int sum(int data[], int n) { int sum=0; for (int i=0; i<n;i++) sum += data[i]; return sum; } The array argument An int parameter of unkown size Size of the array