Constructor overloading in C Sharp (C#) - Step-by-Step Execution

Concept Flow - Constructor overloading

Create object

↓

Check constructor parameters

↓

No params

↓

Call matching constructor

↓

Initialize object fields

↓

Object ready to use

When creating an object, the program chooses the constructor that matches the given parameters to initialize the object properly.

Execution Sample

C Sharp (C#)

class Box {
  int length, width;
  public Box() { length = 1; width = 1; }
  public Box(int l) { length = l; width = 1; }
  public Box(int l, int w) { length = l; width = w; }
}

Defines a Box class with three constructors: no parameters, one parameter, and two parameters.

Execution Table

Step	Constructor Called	Parameters	Field length	Field width	Action
1	Box()	none	1	1	Default constructor sets length=1, width=1
2	Box(int l)	5	5	1	Constructor with one parameter sets length=5, width=1
3	Box(int l, int w)	5, 10	5	10	Constructor with two parameters sets length=5, width=10
4	Exit	-	-	-	All constructors executed as per parameters

💡 Execution stops after all constructor calls are demonstrated.

Variable Tracker

Variable	Start	After 1	After 2	After 3	Final
length	undefined	1	5	5	5
width	undefined	1	1	10	10

Key Moments - 3 Insights

Why does the constructor with one parameter set width to 1?

Because in the constructor Box(int l), width is explicitly set to 1, as shown in step 2 of the execution_table.

What happens if no constructor matches the parameters?

The program will give an error. Here, each constructor matches the parameters given, so no error occurs (see step 4 exit note).

How does the program decide which constructor to call?

It looks at the number and type of parameters when creating the object and calls the matching constructor, as shown in the concept_flow and execution_table.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of width after step 2?

A 1

B 5

C 10

D undefined

💡 Hint

Check the 'Field width' column in row 2 of the execution_table.

At which step does the constructor set length to 5 and width to 10?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Constructor Called' and 'Field width' columns in the execution_table.

If we create a Box object with no parameters, what will length be according to variable_tracker?

A undefined

B 1

C 5

D 10

💡 Hint

Check the 'After 1' column for 'length' in variable_tracker.

Concept Snapshot

Constructor overloading allows multiple constructors with different parameters.
The program calls the constructor matching the given arguments.
Each constructor initializes object fields differently.
This helps create objects in flexible ways.
Syntax: multiple constructors with different parameter lists.

Full Transcript

Constructor overloading means a class can have several constructors with different parameters. When you create an object, the program picks the constructor that matches the parameters you give. For example, a Box class can have a constructor with no parameters that sets default size, one parameter to set length, and two parameters to set length and width. The execution table shows how each constructor sets the fields length and width. The variable tracker shows how these fields change after each constructor call. This helps beginners understand how the program chooses and runs the right constructor to build the object.