Csharp/CSharp Tutorial/Operator Overload/Cast operator — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Текущая версия на 12:18, 26 мая 2010
explicit/implicit operator for Complex
using System;
public struct Complex
{
public Complex( double real, double imaginary ) {
this.real = real;
this.imaginary = imaginary;
}
// System.Object override
public override string ToString() {
return String.Format( "({0}, {1})", real, imaginary );
}
public double Magnitude {
get {
return Math.Sqrt( Math.Pow(this.real, 2) + Math.Pow(this.imaginary, 2) );
}
}
public static implicit operator Complex( double d ) {
return new Complex( d, 0 );
}
public static explicit operator double( Complex c ) {
return c.Magnitude;
}
private double real;
private double imaginary;
}
public class EntryPoint
{
static void Main() {
Complex cpx1 = new Complex( 1.0, 3.0 );
Complex cpx2 = 2.0; // Use implicit operator.
double d = (double) cpx1; // Use explicit operator.
Console.WriteLine( "cpx1 = {0}", cpx1 );
Console.WriteLine( "cpx2 = {0}", cpx2 );
Console.WriteLine( "d = {0}", d );
}
}
cpx1 = (1, 3) cpx2 = (2, 0) d = 3.16227766016838
implicit and explicit operator cast
using System;
class MyType
{
int value;
public MyType( int b )
{
value = b;
}
public static implicit operator int( MyType a )
{
return a.value;
}
public static explicit operator string( MyType a )
{
return "$" + a.value;
}
static void Main(string[] args)
{
MyType bal = new MyType( 777 );
Console.WriteLine("since int conversion is implicit we can write");
int i = bal;
Console.WriteLine("string conveersion must be explicitly requested");
string str = (string)bal;
// this causes a compilation error
// str = bal;
System.Console.WriteLine( "i = {0} \nstr = {1}", i, str );
}
}
since int conversion is implicit we can write string conveersion must be explicitly requested i = 777 str = $777