Reference Variables.

Reference variables allow two variable names to address the same memory location. The following example shows the technique in its simplest form. 

        
    #include 
    
    main()
    {
        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.

Examples:

o Example program.

o Example C program.

See Also:

C References

o data types.

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Martin Leslie 29-Sep-96