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Software fundamentals

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Susan Winters
Susan Winters

The very basics of Software Development Fundamentals. (A prerequisite of learning Object Oriented Programming).

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Software Development Fundamentals Susan Winters
Software Development Application Life-Cycle Management Application Specifications Computer Storage Data Structures Algorithms Decision Making Repetition
Application Life-Cycle Development Envision I want a program that will do this and that Requirements This is what the program must do and include; document it! Design site architecture story boards dictate the flow - mockups Development coders writes out technical specs what technologies will be used, etc. Test unit testing test code snippets. Full testing does the program do what its supposed to do? UAT User Acceptance Testing users play with software to test if it works for users. User friendly? Deploy move from development to production out to the public Maintain fixing bugs found after launch. patches, enhancements, etc.
Computer Storage & Processing Understanding computer storage helps you understand why we use data types and why there are restrictions on those data types. Computers deal with BINARY concepts (off/on) Bit 0 or 1 (off/on) Bytes - groups of bits Computer Memory we can only load a finite amount of data into the computer at one time. ASCII chart a way to represent special characters in binary
How the computer understands code Programming Languages allow you to write your programs in an English style syntax to represent data and instructions that is then compiled and exports that code into a binary version of instructions that the computer understands. Dont worry about how the compiler takes care of this translation. Specific computer platforms have specific processing sets so inside the CPU the computer will know how to process the instructions. Instruction sets and compilers
Variables Provides a temporary, named storage location in memory that youll refer to in your code to access the data in storage Name Storage locations that we refer to in our code that will be mapped to these memory locations You can change the values assigned to the variable Variables are just holders of data you want to store in memory and can access later when needed.
Constants Constants like variables hold in memory data that you can retrieve later however you can not change the value of them. Example: _______________ (list price) x 8.25% (sales tax) = ______________ (total price) A programmer can put the tax rate into a program and do calculations based on the other variables in the calculation but the tax rate is never changed while the program is running. It remains constant.
Data Types Data Type Range Description byte 0 to 255 A single byte (8 bits) char Any Unicode character Characters used in most languages in the world short -32,768 to 32,767 Signed integer values int -2,147,483,648 to 2,147,483,647 Larger signed integer values long 9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 Even larger signed integer values float +/- 1.5 x 10-45 to +/- -3.4 x 1038 Floating point signed values double +/- 5.0e-324 to +/- 1.7e308 Large floating point signed values string String of characters Words, sentences, phrases, etc. boolean True or False Represents true or false, 1 or 0
Data Structure Types Arrays Stacks Queues Dictionaries - Data structures are represented by a variable
Arrays An array is a group / collection of similar data types. Arrays are designed to store the same data type A collection of string values or a collection of number values Random access data structure Accessed thru indexes; Access any value in any order by using the index value. Index numbers starts with Zero not One! In the photo above you see a collection of brick toys. Some bricks are the same color, some have the same number of pegs but they are all the same type of toy so they can be placed in an array. (abstract) Imagine each brick had its own serial number You could pick out a specific individual brick by its serial number (ie. Index number assigned by a programmer).
Stacks A collection of objects, accessed by pop and push. To the right you see a stack of books. You push a book down on top of the stack of existing books. To get a book, you must pop the books off of the stack one at a time starting with the one on top. First in, Last out
Queue A collection of objects, accessed by queuing and de-queuing. Similar to people standing in line. You add another person to the que (line) with en-queue and you get a person out of line (the person in the first position) with de- queue Each object (person) in the collection (line) is processed in the order in which they got into the collection (line). First in, First out.
Dictionary Key Value Key1 First item Key2 Second item Key3 Third item A collection of objects that are accessed by using a key. Looks similar to an array. Key Value firstName Susan lastName Winters eyeColor hazel
Algorithms A set of instructions a solution to a problem They can be recipes, mathematical calculations or other formulas Think logically of how to solve a problem / accomplish a goal Visualize your algorithms in a flow chart before you start coding so that you can catch bugs in your code.
Decision Structures Your code will always be asking questions Is x > y? (mathematical yes or no) Is eyColor = hazel? (exact match) Which color is most desirable? Red, Orange or Blue? (select one) If, if-else, if-else-if Switch or Select Case You can change the flow of your program code based on the outcome of a decision structure. X Red Blue Color? Y> Orange
Repetition Keep doing something until I tell you to stop. For loops While loops Do-while loops Recursion Use a counter (i or other variable name) to represent the number of times your code has looped.) An infinite loop is one that never ends. Dont do that! Youll eventually run out of memory and crash the application and the computer will quit processing.
For Loops for(int myCounter = 0; myCounter < 10; myCounter++) { //do something } For each value in this range that Im working with do something; Check to see if the number of times Ive done something is less than 10; Add 1 to the counter after each time something has been done. (in this range is 10 in this scenario This is the condition you are checking).
While Loops while (myCounter < 10) { //do something console.write(Counter is at + myCounter); // increment the counter here myCounter++; } While my condition is true do something; Then increment my counter. (my condition in this scenario is the counter being less than 10).
Do-While Loops myCounter = 1; do { //something console.write(hello); // increment the counter here myCounter++; } while (myCounter < 5); Do this (at least once) and then increment myCounter. Then keep doing it while myCounter < 5. (my condition to continuing to do something after the first time - in this scenario - is the myCounter being less than 5).
Recursive long value = Factorial(5); console.writeLine(value); static long Factorial(int x) { if (z ==0) {return 1;} return z * Factorial(z 1) Factorial means Im going to take a range of values and multiply them together. You tell the Factorial function what the highest number in the range is (in this scenario its 5). So your answer would be 1 x 2 x 3 x 4 x 5 = 120
This information can be used to help you pass the Microsoft Exam 98-361 Susan Winters

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Software fundamentals

  • 2. Software Development Application Life-Cycle Management Application Specifications Computer Storage Data Structures Algorithms Decision Making Repetition
  • 3. Application Life-Cycle Development Envision I want a program that will do this and that Requirements This is what the program must do and include; document it! Design site architecture story boards dictate the flow - mockups Development coders writes out technical specs what technologies will be used, etc. Test unit testing test code snippets. Full testing does the program do what its supposed to do? UAT User Acceptance Testing users play with software to test if it works for users. User friendly? Deploy move from development to production out to the public Maintain fixing bugs found after launch. patches, enhancements, etc.
  • 4. Computer Storage & Processing Understanding computer storage helps you understand why we use data types and why there are restrictions on those data types. Computers deal with BINARY concepts (off/on) Bit 0 or 1 (off/on) Bytes - groups of bits Computer Memory we can only load a finite amount of data into the computer at one time. ASCII chart a way to represent special characters in binary
  • 5. How the computer understands code Programming Languages allow you to write your programs in an English style syntax to represent data and instructions that is then compiled and exports that code into a binary version of instructions that the computer understands. Dont worry about how the compiler takes care of this translation. Specific computer platforms have specific processing sets so inside the CPU the computer will know how to process the instructions. Instruction sets and compilers
  • 6. Variables Provides a temporary, named storage location in memory that youll refer to in your code to access the data in storage Name Storage locations that we refer to in our code that will be mapped to these memory locations You can change the values assigned to the variable Variables are just holders of data you want to store in memory and can access later when needed.
  • 7. Constants Constants like variables hold in memory data that you can retrieve later however you can not change the value of them. Example: _______________ (list price) x 8.25% (sales tax) = ______________ (total price) A programmer can put the tax rate into a program and do calculations based on the other variables in the calculation but the tax rate is never changed while the program is running. It remains constant.
  • 8. Data Types Data Type Range Description byte 0 to 255 A single byte (8 bits) char Any Unicode character Characters used in most languages in the world short -32,768 to 32,767 Signed integer values int -2,147,483,648 to 2,147,483,647 Larger signed integer values long 9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 Even larger signed integer values float +/- 1.5 x 10-45 to +/- -3.4 x 1038 Floating point signed values double +/- 5.0e-324 to +/- 1.7e308 Large floating point signed values string String of characters Words, sentences, phrases, etc. boolean True or False Represents true or false, 1 or 0
  • 9. Data Structure Types Arrays Stacks Queues Dictionaries - Data structures are represented by a variable
  • 10. Arrays An array is a group / collection of similar data types. Arrays are designed to store the same data type A collection of string values or a collection of number values Random access data structure Accessed thru indexes; Access any value in any order by using the index value. Index numbers starts with Zero not One! In the photo above you see a collection of brick toys. Some bricks are the same color, some have the same number of pegs but they are all the same type of toy so they can be placed in an array. (abstract) Imagine each brick had its own serial number You could pick out a specific individual brick by its serial number (ie. Index number assigned by a programmer).
  • 11. Stacks A collection of objects, accessed by pop and push. To the right you see a stack of books. You push a book down on top of the stack of existing books. To get a book, you must pop the books off of the stack one at a time starting with the one on top. First in, Last out
  • 12. Queue A collection of objects, accessed by queuing and de-queuing. Similar to people standing in line. You add another person to the que (line) with en-queue and you get a person out of line (the person in the first position) with de- queue Each object (person) in the collection (line) is processed in the order in which they got into the collection (line). First in, First out.
  • 13. Dictionary Key Value Key1 First item Key2 Second item Key3 Third item A collection of objects that are accessed by using a key. Looks similar to an array. Key Value firstName Susan lastName Winters eyeColor hazel
  • 14. Algorithms A set of instructions a solution to a problem They can be recipes, mathematical calculations or other formulas Think logically of how to solve a problem / accomplish a goal Visualize your algorithms in a flow chart before you start coding so that you can catch bugs in your code.
  • 15. Decision Structures Your code will always be asking questions Is x > y? (mathematical yes or no) Is eyColor = hazel? (exact match) Which color is most desirable? Red, Orange or Blue? (select one) If, if-else, if-else-if Switch or Select Case You can change the flow of your program code based on the outcome of a decision structure. X Red Blue Color? Y> Orange
  • 16. Repetition Keep doing something until I tell you to stop. For loops While loops Do-while loops Recursion Use a counter (i or other variable name) to represent the number of times your code has looped.) An infinite loop is one that never ends. Dont do that! Youll eventually run out of memory and crash the application and the computer will quit processing.
  • 17. For Loops for(int myCounter = 0; myCounter < 10; myCounter++) { //do something } For each value in this range that Im working with do something; Check to see if the number of times Ive done something is less than 10; Add 1 to the counter after each time something has been done. (in this range is 10 in this scenario This is the condition you are checking).
  • 18. While Loops while (myCounter < 10) { //do something console.write(Counter is at + myCounter); // increment the counter here myCounter++; } While my condition is true do something; Then increment my counter. (my condition in this scenario is the counter being less than 10).
  • 19. Do-While Loops myCounter = 1; do { //something console.write(hello); // increment the counter here myCounter++; } while (myCounter < 5); Do this (at least once) and then increment myCounter. Then keep doing it while myCounter < 5. (my condition to continuing to do something after the first time - in this scenario - is the myCounter being less than 5).
  • 20. Recursive long value = Factorial(5); console.writeLine(value); static long Factorial(int x) { if (z ==0) {return 1;} return z * Factorial(z 1) Factorial means Im going to take a range of values and multiply them together. You tell the Factorial function what the highest number in the range is (in this scenario its 5). So your answer would be 1 x 2 x 3 x 4 x 5 = 120
  • 21. This information can be used to help you pass the Microsoft Exam 98-361 Susan Winters