This Keyword

This Keyword is used To inform the compiler that you wish to

set the current object’s

name data field to the incoming name parameter, simply use this to resolve

the ambiguity:

public void SetDriverName(string name)

{ this.name = name; }

Chaining Constructor Calls Using this

Another use of the

this keyword is to design a class using a technique termed constructor chaining.

This design pattern is helpful when you have a class that defines multiple constructors. Given the

fact that constructors often validate the incoming arguments to enforce various business rules, it

can be quite common to find redundant validation logic within a class’s constructor set.

A cleaner approach is to designate the constructor that takes the

greatest number of arguments

as the “master constructor” and have its implementation perform the required validation logic. The

remaining constructors can make use of the

this keyword to forward the incoming arguments to

the master constructor and provide any additional parameters as necessary. In this way, we only

need to worry about maintaining a single constructor for the entire class, while the remaining constructors

are basically empty.

Here is the final iteration of the

Motorcycle class (with one additional constructor for the sake

of illustration). When chaining constructors, note how the

this keyword is “dangling” off the constructor’s

declaration (via a colon operator) outside the scope of the constructor itself:

class Motorcycle

{

public int driverIntensity;

public string driverName;

// Constructor chaining.

public Motorcycle() {}

public Motorcycle(int intensity)

: this(intensity, "") {}

public Motorcycle(string name)

: this(0, name) {}

// This is the 'master' constructor that does all the real work.

public Motorcycle(int intensity, string name)

{

if (intensity > 10)

{

intensity = 10;

}

driverIntensity = intensity;

driverName = name;

}

...

}

Observing Constructor Flow

On a final note, do know that once a constructor passes arguments to the designated master constructor

(and that constructor has processed the data), the constructor invoked originally by the

caller will finish executing any remaining code statements.