Reference variables allow two variable names to address the same memory location. The following example shows the technique in its simplest form.
#includemain() { int var1; int &var2 = var1; // var2 is a reference variable. var1 = 10; cout << "var1 = " << var1 << endl; cout << "var2 = " << var2 << endl; }
Generally, you would not use a reference variable in this way. Its more likely that they would be used in function parameter lists to make the passing of pointers more readable.
This gives C++ the ability to provide a different approch to changing a variable from within a function. Consider the two following programs.
#include <stdio.h>
void Square(int *pVal);
main()
{
int Number=10;
printf("Number is %d\n", Number);
Square(&Number);
printf("Number is %d\n", Number);
}
void Square(int *pVal)
{
*pVal *= *pVal;
printf("Number is %d\n", *pVal);
}
#include <stdio.h>
void Square(int &Val);
main()
{
int Number=10;
printf("Number is %d\n", Number);
Square(Number);
printf("Number is %d\n", Number);
}
void Square(int &Val)
{
Val *= Val;
printf("Number is %d\n", Val);
}
The program on the right should be clearer to read because you do not need to worry about pointer dereferencing.
o data types.