![Continue…
Following constructor:
string::string(char*a)
{
length=strlength(a);
p=new char[length+1];
strcpy(p,a);
}
The statement
s1=string(name 1);
First converts name1 from char* type and then values the
assign the strings type values to the objects S1
S2=Name 2;](https://image.slidesharecdn.com/operatoroverloadingandtypeconversionincpp-190928132026/85/Operator-overloading-and-type-conversion-in-cpp-17-320.jpg)
Operator overloading and type conversion in cpp
- 1. D.SHANMUGAPRIYA I- M.Sc(IT) OPERATOR OVERLOADING AND TYPE CONVERSION
- 2. OPERATOR OVERLOADING AND TYPE CONVERSION INTRODUCTION DEFINING OPERATOR OVERLOADING OVERLOADING UNARY OPERATORS OVERLOADI NG BINARY OPERATORS OVERLOADING BINARY OPERATORS USING FRIENDS SOME OTHER OPERATOR OVERLOADING EXAMPLES RULES FOR OVERLOADING OPERATORS TYPE CONVERSION
- 3. INTRODUCTION Operator overloading is one of the many exciting features of the C++ language. Operator overloading provides a flexible option for the creation of new definition for most of the C++ operators. Class member access operator(.,.*) Scope resolution operator(::) Size operator(size of) Conditional operator(?:)
- 4. DEFINNING OPERATOR OVERLOADING We must specify what it means in relation to the class to which the operator is applied. Syntax: Return type classname::operator op(arglist) { function body//task defined } Operator functions must be either member functions or friend functions: vector operator+(vector);//vectoraddition Vector operator-(vector)://unary minus
- 5. CONTINUE…. Friend vector operator+(vector;vector); //vector addition Friend vector operator-(vector); //unary minus Vector operator-(vector&a); //subtraction Int operator==(vector,vector); //comparison The process of overloading involves the following steps: Create a class that defines the datatype that is to be used in the overloading operation. Declare the operator functions operator op() in the public part of the class. UNARY OPERATOR=X OP Y BINARY OPERATOR=OPERATOR OP(X)
- 6. OVERLOADING UNARY OPERATORS A minus operator when use as a unary takes just one operand. Remember a statement like It is possible to overload a unary minus operator using a friend function as follows: Friend void operator-(space&s); void operator-(space&s) S2=-S1; S.X=-S.X; S.Y=-S.Y; S.Z=-S.Z;
- 7. Example:
- 8. OVERLOADING BINARY OPERATORS The same mechanism can be used to overload a binary operator. C1 takes the responsibility of invoking the function and c2 plays the role of an argument that is passed to the function. Both the objects are available for the function. C=SUM(A,B); C3=C1.OPERATOR+(C2); TEMP.X=X+C.X;
- 9. Example:
- 10. IMPLEMENTED OF THE OVERLOAD BINARY OPERATOR:
- 11. OVERLOADING BINARY OPERATORS USING FRIENDS Friend functions may be used in the place of member functions for overloading a binary operator. 1) Replace the member function declartion by the friend function declaration 2) [friend complex operation+(complex,complex); 3) Redefine the operator function as followa: [complex opearor+(complex a,complex b) { return complex((a.x+b.x),(a.y+b.y)); } In this case the statement C3=C1+C2; C3=OPERATOR+(C1+C2);
- 12. MANIPULATION OF STRINGS USING OPERATORS ANSI C implements strings using character arrays,pointers and string functions. EXAMPLE: Thus we must create string objects that we can hold these two pieces of information. Class string { Char*p; Int len; Public: } String3=string1+string2; If(string 1>=string2)string=string1;
- 14. SUB TOPICS OVERLOADING THE SUBSCRIPT OPERATOR o The subscript operator is normally used to access and modify a specific element in an array. OVERLOADING THE POINTER TO MEMBER - >OPERATOR: o The pointer to member operator is normally used to conjunction with an object pointer to access any of the objects member.
- 15. RULES FOR OVERLOADING OPERATOR There are certain restrictions and limitations in overloading them,some of them are listed below Only existing operators can be overloaded Overloaded operators follow the syntax rules of the original operators. There are some operators that cannot be overloaded. SIZE OF SIZE OF OPERATOR . Membership operator .* pointer to member operator :: scope resolution operator ?: conditional operator
- 16. TYPE CONVERSION The type of data to the right of an assignment operator is automatically converted to the type of the variable on the left. BASIC TO CLASS TYPE: 1) It may be recalled that the use of constructor was illustrated in a number of examples to initialize objects. int m; float x=3.14159; m=x;
- 17. Continue… Following constructor: string::string(char*a) { length=strlength(a); p=new char[length+1]; strcpy(p,a); } The statement s1=string(name 1); First converts name1 from char* type and then values the assign the strings type values to the objects S1 S2=Name 2;
- 18. T H A N K y O U