Object Containing objects

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

Inheritance_Rectangle Shapes

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

Intro_To_Inheritance

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

HTML

<!-- Adding <optgroup> tag to the dropdown list element. this tag allows you to group your list by category
            -->
        <p>
            Adding &lt;optgroup&gt; tag to the dropdown list element. this tag allows you to group your list by category
        </p>
        <select name="cars">
            <optgroup label="Japanese Cars">
                <option value="Toyota">Toyota</option>
                <option value="Honda">Honda</option>
                <option value="Nissan">Nissan</option>
            </optgroup>
            <optgroup label="Sweedish Cars">
                <option value="Volvo">Volvo</option>
                <option value ="Saab">Saab</option>
            </optgroup>
            <optgroup label="German Cars">
                <option value="BMW">BMW</option>
                <option value="Mercedes">Mercedes</option>
                <option value="Audi">Audi</option>
            </optgroup>
            <optgroup label="American Cars">
                <option value="Ford">Ford</option>
                <option value="Chevrolet">Chevrolet</option>
            </optgroup>
        </select>
        <br /> <br />

        <textarea rows="10" cols="20" maxlength="256" wrap="soft" placeholder="Enter Comment"></textarea>

Object Containing Other Objects

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

BinaryReadWrite_LabAssignment

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

BinaryReaderWriter

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;