2. Pseudocode 2. Pseudocode2. Pseudocode2. Pseudocode.pptx
- 1. Computer Programming 1 – Information Technology CMO 25 s. 2015
- 2. Recap A brief history of women in Software Engineering
- 3. Pseudocode What is pseudocode What is algorithm Advantages of pseudocode How to write pseudocode Pseudocode Flow of control
- 4. Specific Objectives By the end of this lesson, you should 1. Write pseudo code for a given problem 2. Display teamwork in completing task 3. Cooperate in group work
- 5. What is pseudocode? is a detailed yet readable description of what a computer program or algorithm must do, expressed in a formally-styled natural language rather than in a programming language. Pseudocode is sometimes used as a detailed step in the process of developing a program.
- 6. Application of pseudocode Textbooks and scientific publications related to computer science and numerical computation often use pseudocode in description of algorithms, so that all programmers can understand them, even if they do not all know the same programming languages. A programmer who needs to implement a specific algorithm, especially an unfamiliar one, will often start with a pseudocode description, and then "translate" that description into the target programming language and modify it to interact correctly with the rest of the program.
- 7. Syntax of pseudocode As the name suggests, pseudocode generally does not actually obey the syntax rules of any particular language; there is no systematic standard form, although any particular writer will generally borrow style and syntax; for example, control structures from some conventional programming language.
- 8. What is algorithm? Algorithm: It’s an organized logical sequence of the actions or the approach towards a particular problem. A programmer implements an algorithm to solve a problem in a specific programming language. Pseudo code: It’s simply an implementation of an algorithm in the form of annotations and informative text written in plain English. It has no syntax like any of the programming language and thus can’t be compiled or interpreted by the computer.
- 9. Advantages of pseudocode Improves the readability of any approach. It’s one of the best approaches to start implementation of an algorithm. Acts as a bridge between the program and the algorithm or flowchart. Also works as a rough documentation, so the program of one developer can be understood easily when a pseudo code is written out. In industries, the approach of documentation is essential. And that’s where a pseudo-code proves vital. The main goal of a pseudo code is to explain what exactly each line of a program should do, hence making the code construction phase easier for the programmer.
- 10. RULES FOR PSEUDOCODE 1. Write only one statement per line 2. Capitalize initial keyword 3. Indent to show hierarchy 4. End multiline structures 5. Keep statements language independent
- 11. RULES FOR PSEUDOCODE 1. Write only one statement per line Each statement in your pseudocode should express just one action for the computer. If the task list is properly drawn, then in most cases each task will correspond to one line of pseudocode. 1 2 3 4 5
- 12. RULES FOR PSEUDOCODE 2. Capitalize initial keyword In the example above, READ and WRITE are in caps. There are just a few keywords we will use: READ, WRITE, IF, ELSE, ENDIF, WHILE, ENDWHILE, REPEAT, UNTIL Input: READ, OBTAIN, GET Output: PRINT, DISPLAY, SHOW Compute: COMPUTE, CALCULATE, DETERMINE Initialize: SET, INIT Add one: INCREMENT, BUMP
- 13. RULES FOR PSEUDOCODE 3. Indent to show hierarchy We will use a particular indentation pattern in each of the design structures: SEQUENCE: keep statements that are “stacked” in sequence all starting in the same column. SELECTION: indent the statements that fall inside the selection structure, but not the keywords that form the selection LOOPING: indent the statements that fall inside the loop, but not the keywords that form the loop
- 14. RULES FOR PSEUDOCODE 4. End multiline structures See how the IF/ELSE/ENDIF is constructed above. The ENDIF (or END whatever) always is in line with the IF (or whatever starts the structure).
- 15. RULES FOR PSEUDOCODE 5. Keep staments language independent Resist the urge to write in whatever language you are most comfortable with. In the long run, you will save time! There may be special features available in the language you plan to eventually write the program in; if you are SURE it will be written in that language, then you can use the features. If not, then avoid using the special features.
- 16. Format ProgramName ComputerSumofTwoNumbers: BEGIN DECLARE num1, num2, sum READ num1, num2 sum is equals to num1 + num2 or sum = num1 +num2 WRITE total END
- 17. Exercises 1. Create a pseudocode that will compute and display the area of a rectangle 2. Create a pseudocode of the activities that you do when you get up in the morning 3. Create a pseudocode on how to cook a noodles 4. Create a pseudocode on how to compute your age 5. Create a pseudocode on how to computer your grades in highschool 6. Create a pseudocode on how to withdraw money from ATM 7. Create a pseudocode that will computer the sum of 5 numbers and then display the average. 8. Write pseudocode that will compute your salary based on the basic formula (salary = (number of days work * rate per day) – deduction) 9. Write a java program that will compute the number of respondents using the sloven’s formula. To compute the number of respondents the user must enter the total population size. Sloven’s formula: n = N/(1+(Ne2)) where: n = number of respondents N = total population e = margin of error , 0.05 in this case
- 18. Flow of Control Sequential flow Selection or Conditional flow Iterative flow
- 20. Selection or Conditional Flow During algorithm development, we need statements which evaluate expressions and execute instructions depending on whether the expression evaluated to True or False. IF — ELSE IF — ELSE This is a conditional that is used to provide statements to be executed if a certain condition is met. This also applies to multiple conditions and different variables. Types of Selection Single Alternative (if statement) Double Alternative (if else statement) Multiple Alternative (if else if statement)
- 24. Basic Math Symbols When we have to make a choice between actions, we almost always base that choice on a test. The test uses phrases like “is less than” or “is equal to”. There is a universally accepted set of symbols used to represent these phrases:
- 25. Logical Operators AND: if any of the conditions are false, the whole expression is false. IF day = “Saturday” AND weather = “sunny” WRITE “Let’s go to the beach!” ENDIF OR: if any of the conditions are true, the whole expression is true IF month = “June” OR month = “July” OR month = “August” WRITE “Yahoo! Summer vacation!” ENDIF NOT: reverses the outcome of the expression; true becomes false, false becomes true. IF day <> “Saturday” AND day <> “Sunday” WRITE “Yuk, another work day” ENDIF
- 26. Single Alternative (if statement)
- 27. Double Alternative (if else statement)
- 28. Multiple Alternative (if else if statement)
- 29. Nested if statement Nested If...Then... Else statements te st for multiple conditions by placing If...Then... Else statements ins ide other If...Then. ..Else statements.
- 32. Exercises 1. Write a pseudocode that will determine if the number is an odd or even number 2. Write a pseudocode that will print passed if the grade is above 74, failed if 74 and below 3. Write a pseudocde that will determine the highest number between two numbers. 4. Write a pseudocde that converts currency to another currency. It is a peso to dollar, dollar to peso converter program. The final result will be the converted amount of the currency. 5. Write a pseudocde that will ask the user to enter 1-10 and call that program as PrintNumberInWord which prints "ONE", "TWO",... , "NINE", "OTHER" if the int variable "number" is 1, 2,... , 9, or other, respectively. Use (a) a "if.elseif.else" statement 6. Write a java program that will ask the user to enter 2 numbers and will ask what operator to use (1 for addition, 2 for subtraction, 3 for division, and 4 for multiplication). It will also print the result. 7. ATM Machine Pseudocode. Suppose you have a balance of 5000 pesos, create a java program that will ask the user to select the transaction he/she want to access, w to withdraw (ask the user to input amount to withdraw and output the new balance), d for deposit (ask the user to input amount to deposit and output the new balance), i for inquiry (display the balance). 8. Writea a pseudocode that will ask the user to enter its grade then display the remarks. 95-100 - excellent 90-94 - very good 85-89 - good 80-84- satisfactory 76-79 - study harder 75 - passed 74 below – failed
- 33. Iterative Flow To iterate is to repeat a set of instructions in order to generate a sequence of outcomes. We iterate so that we can achieve a certain goal. Types of Iteration for loop while loop do-while loop
- 35. Assessment By the end of this lesson, you should 1. Write pseudo code for a given problem – Quiz and Exercises 2. Display teamwork in completing task – Project and Reporting 3. Cooperate in group work - Project and Reporting