DCIT22 Introduction to Program Logic Formulation and Program Coding (Pseudocode) PDF

DCIT22-Computer Programming I Lesson 1: Introduction to Program Logic Formulation and Program Coding (Pseudocode) Prepared by: Ms.Mariella R. Leyba, MIT  OBJECTIVES After the completion of the chapter, students will be able to: 1. Understand the algorithms, as part of software development;...

DCIT22-Computer Programming I Lesson 1: Introduction to Program Logic Formulation and Program Coding (Pseudocode) Prepared by: Ms.Mariella R. Leyba, MIT  OBJECTIVES After the completion of the chapter, students will be able to: 1. Understand the algorithms, as part of software development; 2. Define and identify the symbols used in flowcharting; 3. Analyze and design pseudocode and flowchart in solving a problem; and 4. Create an algorithms, pseudocode, and flowchart in solving a problem. ALGORITHMS It is a step by step instructions to solve a specific problem. ALGORITHMS How to get ready for school: 1. Wake up. 2. Eat breakfast. 3. Practice good hygiene. 4. Get dressed. 5. Take everything you need. 6. Head out the door. 7. Ride your school bus.  “An algorithm is a representation of a solution to a problem.” There are two commonly used tools to help document program logic (the algorithm): 1. Pseudocode 2. Flowchart PSEUDOCODE - is simply a numbered list of instructions to perform some task. - it is a simpler version of a programming code in plain English before it is implemented in a specific programming language. - it is meant to be a high-level way of representing an algorithm without tying it to a specific language. PSEUDOCODE Ways of Writing a Pseudocode: 1. Number each instruction; ○ This is to enforce the notion of an ordered sequence of operations. ○ Furthermore we introduce a dot notation (e.g. 3.1 comes after 3 but before 4) to number subordinate operations for conditional and iterative operations 2. Each instruction should be unambiguous and effective; and 3. Completeness. Nothing is left out. Basic Elements of Pseudocode: 1. Variable - having a name and value. Example: number = 1 (name) (value) - There are two operations performed on a variable. Assignment Operation Read Operation Basic Elements of Pseudocode: 2. Assigned Operation - the one which associates a value to a variable. - While writing Pseudo-code you may follow your own syntax. Some of the possible syntaxes are: - Assign 1 to number - Set number equal to 1 Pseudocode: Step 1: Start 1.Example: number = 1 Step 2: Assign 1 to number. (name) (value) Step 3: End Pseudocode: first_name = “Mariella” Step 1: Start (name) (value) Step 2: Set first_name is equal to “Mariella”. Step 3: End Basic Elements of Pseudocode: 3. Read Operation - intends to retrieve the value previously assigned to that variable. Example: - Set the value of num1 equal to the value of num2. Operation:num1 = 5 num2 = 6 Pseudocode: Step 1: Start num1 = num2 Step 2: Assign 5 to num1. Output: num1 = 6 Step 3: Assign 6 to num2. Step 4: Set the value of num1 equal num2 = 6 to the value of num2. Step 5: End Basic Elements of Pseudocode: 4. Read the input from user - get the value of a variable from the user Example #1: Example #2:(STRING) 1. Operation: number(variable) 2. Operation: name(variable) Enter a number: 5 Enter your name: JOSH Output: number = 5 Output: name = “JOSH” Pseudocode: Step 1: Start Pseudocode: Step 2: Print “Enter a number:”, number. Step 1: Start Step 3: End Step 2: Print “Enter a your name:”, name. Step 3: End Basic Elements of Pseudocode: 5. Print the output to the user - Print x (This will print value of variable x) - Print “Your mileage is” x Operation: name (variable) Enter your name: JUNIOR name= “JUNIOR” Pseudocode: Output: HELLO JUNIOR Step 1: Start Step 2: Print “Enter a your name:”, name Step 3: Print “HELLO”, name. Step 4: End Basic Elements of Pseudocode: *Carry out basic arithmetical computation Example - Add num1 and num2 - Subtract num2 from num1  Example: Pseudocode for adding two numbers. Step 1: Begin. Step 2: Print “Enter first number:”, num1. Step 3: Print “Enter second number:”, num2. Step 4: Add num1 and num2 for the value of sum. Step 5: Print “The sum is “, sum. Step 6: Quit. num1 = 10 Enter first number: 10 num2 = 5 Enter second number: 5 sum = num1 + num2 The sum is 15 sum= 15 EXAMPLES BASIC ARITHMETIC nname = “Ella” fnum = 10 snum = 5 difference = fnum - snum PSEUDOCODE - Step 1: Start - Step 2: Print “Enter your nickname”, nname. - Step 3: Print “Enter first number:”, fnum. - Step 4: Print “Enter second number:”, snum. - Step 5: Subtract snum from fnum for the value of difference. - Step 6: Print “Good day,”, nname, “!”. - Step 7: Print “The difference of”, fnum, “and “, snum, “is “, difference - Step 8: End DECISION MAKING fnum = 6 snum = 3 PSEUDOCODE - Step 1: Start - Step 2: Print “Enter first number:”, fnum. - Step 3: Print “Enter second number:”, snum. - Step 4: If fnum is greater than the value of snum. - Step 4.1: Print fnum, “ is greater than “, snum. - Step 5: Else, print snum, “ is greater than “, fnum. - Step 6: End LOOPING current_year = 2020 name = “Mariella” birth_year = 1998 age = current_year - birth_year PSEUDOCODE - Step 1: Start - Step 2: Read current_year=2020 - Step 3: Print “Enter your name:”, name - Step 4: Print “Enter your birth year:”, birth_year - Step 5: The value of age is equal to current_year minus birth_year. - Step 6: Print “Hi”, name, “! You are ”, age, “ years old this year 2020.” - Step 7: Print “Do you want to try again? (Y or N)”, answer - Step 8: Check if answer is equals to ‘Y’. - Step 8.1: Then, go to Step 3. - Step 9: Else, print “Thank you!” - Step 10: End Thank you and God bless!  ___