CT Revision Lecture & MCQs

Detailed Concepts with Examples

Iteration

Iteration involves repeatedly moving data from one set to another while performing a specific action each time. For example, if you have a pile of cards, you can iterate through each card, perform a specific action (e.g., increment a counter), and move the card to a new pile.

Filtering

Filtering involves selecting specific data from a larger dataset based on certain conditions. For instance:

• To get the math marks of all students in a dataset.
• To get the math marks of all girl students.
• To get the math marks of all girl students from Kolkata.

Multiple Filtering

Multiple filtering applies more than one condition to filter data. For example, to get the number of female students from Chennai, you filter by gender (female) and then by city (Chennai).

Flowcharts

Flowcharts are pictorial representations of algorithms with different types of boxes:

• Rectangular Box: Represents processes or activities (e.g., arithmetic operations, assigning values).
• Arrow: Represents the flow of execution.
• Diamond Box: Represents decision points, can have "yes" or "no" outcomes.
• Oval Box: Represents start and end points.

Data Types

Data types categorize the kinds of values that variables can hold:

• Integer: Whole numbers (positive, negative, zero).
• Character: Single alphabetic or numeric characters.
• String: Sequences of characters.
• Boolean: Values true or false.

Boolean Operations

Boolean variables can be used in logical operations:

• AND: Both conditions must be true (1 AND 1 = 1).
• OR: At least one condition must be true (1 OR 0 = 1).

Integer Data Type

Integers can range from negative infinity to positive infinity. Operations include addition, subtraction, multiplication, and division. Comparisons yield Boolean results.

Character Data Type

Characters include letters (A-Z, a-z) and digits (0-9), and special characters (@, #, $, etc.). Operations are limited to comparisons.

String Data Type

Strings are sequences of characters enclosed in quotations. Operations include comparisons and concatenations.

Sub Data Types

Sub data types are specialized versions of basic data types with limited ranges:

• Sequence Number: Typically starts from zero and increments.
• Marks: Range from 0 to 100.

Key Concepts and Formulas

• Iteration: Repeating a set of actions for each item in a dataset.
• Filtering: Extracting specific data based on conditions.
• Flowcharts: Visual representation of algorithms.
• Data Types:
  • Integer: int x = 5;
  • Character: char c = 'a';
  • String: String s = "hello";
  • Boolean: boolean flag = true;
• Boolean Logic:
  • AND: if (condition1 && condition2) {...}
  • OR: if (condition1 || condition2) {...}
• Operations on Data Types:
  • Addition: int sum = a + b;
  • Subtraction: int diff = a - b;
  • Comparison: if (a < b) {...}

Multiple Choice Questions (MCQs)