ISTM 250 | FINAL EXAM QUESTIONS WELL ANSWERED LATEST UPDATE 2026

ISTM 250 | FINAL EXAM QUESTIONS WELL ANSWERED LATEST UPDATE 2026 List Box - Answers lst Enter a list, user can choose from the list Items, Collection Property to enter strings in list (separate by enter) Sorted Property to alphabetize list Interface Goals - Answers Limit human error (list box for available options) Combo Box - Answers cbo Drop down menu Items, Collection Property to enter strings in list (separate by enter) Sorted Property to alphabetize list Drop Down Property to change selection option (list for no typing options) Checkbox - Answers chk, can select multiple Radio Buttons - Answers rad OR rdo, MUTUALLY EXCLUSIVE, select only one Radio buttons that aren't in the group box function as a separate group Group Box - Answers CREATE group of radio buttons! (No need to rename) Selects radio boxes to remove mutual exclusivity, select one in that box, select one from unboxed group. Radio Button Properties - Answers name.Checked (t/f) - determine if checked Found with private bool (name.Checked - returns true if checked) List Box & Combo Box Properties - Answers SelectedIndex/Item - RETRIEVE ITEM Text Sorted Items DropDownStyle SelectionMode List Box & Combo Box Events - Answers SlectedIndexChanged TextChanged Add Item to combo box - Answers cboName.Items.Add (specify item, add from list/array) Best with foreach loop (.Add(loop item name)) Radio Buttons Event - Answers CheckChanged Creates/displays additional dialogue box after creating base dialogue box - Answers Form CustomName = new RealFormName(); CustomName.ShowDialogue (); Tag Property - Answers OBJECT TYPE: From: Gets/sets data in a form (reference to object type), applicable to any type (cast to datatype), or ToString DialogueBox Enumeration: - Answers Represents values a dialogue box can return (ShowDialogue method returns member of this enumeration) DialogResult = Result (can be set to a button for clicks) Closing = puts results into other form (returns cancel value if not set to form) Enumerations - Answers MessageBoxButtons MessageBoxIcons MessageBoxDefaultButton DialogueResult Naming a Class: - Answers Capital letters @ beginning Naming custom properties vs. fields: - Answers Fields need prefix + uppercase name Properties just uppercase Inheritance - Answers Taking a base class (public) and creating DERIVED CLASSES from them Keep preestablished properties & methods, add new properties & methods Simplifies application design Creating subclasses Step 1: - Answers Declare: subclass: baseclass Constructor Blank: public subname(){} Constructor w/ base constructor: public subclassName (parameters) : base (parameters) this.Property = field (same as base class) Call base class method/property: - Answers base.Method(parameters) base.Property() All objects have access to the base class properties and methods Hide non-virtual method/property: - Answers public new type Override virtual method/property: - Answers public override type After subclass constructor: - Answers Go onto properties, overrides/virtual, methods Type Class Properties: - Answers .Name - string, name of type .FullName - string: namespace name & type name .BaseType - Type that represents the class .Namespace - namespace that contains the type Type Class Methods: - Answers GetType(fullname) - Type object for specified name when subclass casting is required: - Answers Not to subclass (part of base) Needed when method accepts baseclass only Abstract classes: - Answers Method has no code after parameters/get Validation no code sub classes can override blank methods in base Override Capacity: - Answers CAN override from base, not other sub classes (sub: sub) Polymorphism - Answers generic code for bases can be rewritten for other sub classes using overrides (also diff subclasses use same base) Treat different subclasses of same base as if they are the same class as base Polymorphism break down: - Answers Base Method: public VIRTUAL ___ Sub Classes: public OVERRIDE ___ (same type/parameters), new type constructed based on sub class-specific variables base = sub - base.Method = sub method Form classes - Answers Different forms are part of the form class Instantiating from newly created class - Answers new ___ name Accessor methods - Answers PUBLIC METHODS. Go back to initial private objects, define them (get/set) Gatekeepers for private data Default values for array elements - Answers BEFORE ADDING/ASSIGNING VALUES: Numeric = 0 Char = '0' (null character) Boolean = false Date Time = 01/01/0001 00:00:00 Reference = null Static class - Answers no objects created from it, already defined with preexisting classes, methods are also static Math Can be called without creating an instance of a class When constructors methods don't have private arguments: - Answers Returns void Virtual methods - Answers Need to be declared in base so it can be overridden in derived classes Combine derived classes - Answers Derived classes can be combined in a list of the base class Starting points for new classes - Answers Object of class they are derived from; SYSTEM LEVEL How to separate lists - Answers One per form/list box Non-virtual methods - Answers Hide methods you don't want to override (new and original per derived class) Inherited Class created vs. taken: - Answers Inherits existing properties, methods, can create new ones. Parameters must be in the same order (new - inherited) Radio buttons vs check boxes - Answers Radio buttons work as a group; check boxes work independently. Buttons NOT placed in group box? - Answers Function as a separate group Display custom dialogue box directly from form - Answers nameForm.ShowDialogue(); Tab Order - Answers Determines the controls on a form receive focus when the user presses the Tab key DialogResult - Answers Enumeration determines how user responded to dialogue box What happens if the event handler for a form's FormClosing event doesn't do anything? - Answers Form is closed To cancel the Form Closing event of a form, you can - Answers Set the Cancel property of the CancelEventArgs object to true Create Class Step 1: - Answers public class Name { Whole rest of code } FIELDS: private type field name; (etc.) Create Class Step 2: - Answers CONSTRUCTORS: EMPTY: public Name(){} CUSTOM: public Name (type fields, etc.) { this.PROPERTY = field; (etc.) } Create Class Step 3: - Answers CODE PROPERTY: public type Property { get { return field; } set { field = value; } } Code Property Parameters WITH exceptions: - Answers set { if (value etc.) { throw exception("Message") } field = value; } Adding form: - Answers public partial class frmName: Form public frmName() { InitializeComponent();