In C# how does one implement the ability to chain methods in one\'s custom classes so one can write something like this:
myclass.DoSomething().DosomethingElse(x)
DoSomething should return a class instance with the DoSomethingElse method.
Chaining is a good solution to produce new instance from existing instances:
public class MyInt
{
private readonly int value;
public MyInt(int value) {
this.value = value;
}
public MyInt Add(int x) {
return new MyInt(this.value + x);
}
public MyInt Subtract(int x) {
return new MyInt(this.value - x);
}
}
Usage:
MyInt x = new MyInt(10).Add(5).Subtract(7);
You can also use this pattern to modify an existing instance, but this is generally not recommended:
public class MyInt
{
private int value;
public MyInt(int value) {
this.value = value;
}
public MyInt Add(int x) {
this.value += x;
return this;
}
public MyInt Subtract(int x) {
this.value -= x;
return this;
}
}
Usage:
MyInt x = new MyInt(10).Add(5).Subtract(7);
Your methods should return this
or a reference to another (possibly new) object depending on exactly what you want to acheive
For a mutable class, something like
class MyClass
{
public MyClass DoSomething()
{
....
return this;
}
}