{"id":619,"date":"2020-05-24T15:48:35","date_gmt":"2020-05-24T15:48:35","guid":{"rendered":"http:\/\/pragmaticways.com\/?page_id=619"},"modified":"2020-05-24T16:35:29","modified_gmt":"2020-05-24T16:35:29","slug":"learning-java-book","status":"publish","type":"page","link":"https:\/\/pragmaticways.com\/learning-java-book\/","title":{"rendered":"Learning Java Book"},"content":{"rendered":"\n\n\n<p><strong>THIS BOOK IS STILL IN BETA STATE. <\/strong><\/p>\n\n\n\n<p>If you&#8217;re interested in becoming a beta tester, please email me at <a href=\"mailto:adam@pragmaticways.com\" class=\"rank-math-link\">adam@pragmaticways.com<\/a> to request a free copy. <\/p>\n\n\n\n<h2>Day 1 Exercises<\/h2>\n\n\n\n<h3>Hello World Program<\/h3>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-java\">public class LearningJava {\n  public static void main(String[] args) {\n    System.out.println(\"Hello World\");\n  } \n}<\/code><\/pre>\n\n\n\n<h3>Greet My Friend Program<\/h3>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-java\">import java.util.Scanner;\n\npublic class GreetMyFriend {\n  public static void main(String[] args) {\n    Scanner input = new Scanner(System.in);\n\n    System.out.println(\"What is your first name? \");\n    String firstName = input.nextLine();\n\n    System.out.println(\"What is your last name? \");\n    String lastName = input.nextLine();\n\n    System.out.println(\"What is your street address? \");\n    String address = input.nextLine();\n\n    System.out.println(\"What city do you live in? \");\n    String city = input.nextLine();\n\n    System.out.println(\"What state do you live in? \");\n    String state = input.nextLine();\n\n    System.out.println(\"What is your favorite color? \");\n    String favoriteColor = input.nextLine();\n\n    System.out.println(\"What is your favorite food? \");\n    String favoriteFood = input.nextLine();\n\n    System.out.println(\"What is your third favorite dinosaur? \");\n    String thirdFavoriteDinosaur = input.nextLine();\n\n    System.out.println(\"First Name: \" + firstName);\n    System.out.println(\"Last Name: \" + lastName);\n    System.out.println(\"Address: \" + address);\n    System.out.println(\"City: \" + city);\n    System.out.println(\"State: \" + state);\n    System.out.println(\"Favorite Color: \" + favoriteColor);\n    System.out.println(\"Favorite Food: \" + favoriteFood);\n    System.out.println(\"Third Favorite Dinosaur: \" + thirdFavoriteDinosaur);\n  }\n}<\/code><\/pre>\n\n\n\n<h2>Day 2 Exercises<\/h2>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-java\">import java.util.Scanner;\nimport java.util.Date;\nimport java.util.Calendar;\nimport java.text.DecimalFormat;\n\npublic class MyClass {\n  public static void main(String []args){\n\n    Scanner input = new Scanner(System.in);\n        \n    System.out.println(\"What is your first name? \");\n    String userFirstName = input.nextLine(); \n        \n    System.out.println(\"What is your middle name? \");\n    String userMiddleName = input.nextLine(); \n    char userMiddleInitial = userMiddleName.charAt(0);\n        \n    System.out.println(\"What is your last name? \");\n    String userLastName = input.nextLine(); \n        \n    System.out.println(\"What year were you born? \");\n    int userBirthYear = input.nextInt();\n        \n    System.out.println(\"true or false: Your birthday already happened this year? \");\n    boolean isPastBirthday = input.nextBoolean(); \n        \n    System.out.println(\"How much money did you get for your birthday? \");\n    double moneyReceivedOnBirthday = input.nextDouble();     \n\t        \n    int userCurrentAge;\n\n\tCalendar calendar = Calendar.getInstance();\n\tcalendar.setTime(new Date());\n    int currentYear = calendar.get(Calendar.YEAR);\n\n    if (isPastBirthday) {\n      userCurrentAge = (currentYear - userBirthYear); \n    } else {\n      userCurrentAge = (currentYear - userBirthYear) - 1;\n    }\n\n\tDecimalFormat moneyFormat = new DecimalFormat(\"0.00\"); \n        \n    String message = \n        \"Hello \" + \n        userFirstName + \" \" + \n        userMiddleInitial + \" \" +\n        userLastName + \"! You are \" + userCurrentAge +\n        \" years old right now. You received $\" +\n        moneyFormat.format(moneyReceivedOnBirthday) + \" on your birthday. Congrats!\";\n            \n    System.out.println(message);\n  }\n}<\/code><\/pre>\n\n\n\n<h2>Unit Conversion Calculator<\/h2>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-java\">package com.company;\n\nimport java.util.InputMismatchException;\nimport java.util.Scanner;\n\npublic class Main {\n\n    public static void main(String[] args) {\n        boolean shouldRunProgram = true;\n        while (shouldRunProgram) {\n            runMainMenu();\n            shouldRunProgram = askToRerunProgram();\n        }\n    }\n\n    private static void runMainMenu() {\n        String unitCategory = askForUnitCategory();\n        String availableUnitsForCategory[] = getAvailableUnitsForCategory(unitCategory);\n        String startingUnit = askForStartingUnit(unitCategory, availableUnitsForCategory);\n        double amountOfStartingUnit = askForAmountOfStaringUnit(startingUnit);\n        String endingUnit = askForEndingUnit(unitCategory, availableUnitsForCategory);\n        double amountOfEndingUnit = convert(unitCategory, startingUnit, amountOfStartingUnit, endingUnit);\n        printResults(startingUnit, amountOfStartingUnit, endingUnit, amountOfEndingUnit);\n    }\n\n    private static String askForUnitCategory() {\n        String promptForUnitCategory = \"\\nWhat category of units do you need to convert?\";\n        String availableUnitCategories[] = {\n                \"LENGTH\", \"TIME\", \"TEMPERATURE\", \"MASS\"\n        };\n        String unitCategory = askForOption(promptForUnitCategory, availableUnitCategories);\n        return unitCategory;\n    }\n\n    private static String askForOption(String prompt, String[] options) { \n        boolean isValidChoice;\n        String choice;\n        do {\n            System.out.print(prompt);\n            System.out.println(\" You can type: \");\n            for (String option : options) {\n                System.out.println(option);\n            }\n            System.out.print(\"Your choice: \");\n\n            Scanner scanner = new Scanner(System.in);\n            choice = scanner.nextLine().toUpperCase();\n\n            isValidChoice = verifyChoiceIsValidOption(choice, options);\n            if (!isValidChoice) {\n                printInvalidOptionError();\n            }\n        } while (!isValidChoice);\n\n        return choice;\n    }\n\n    private static boolean verifyChoiceIsValidOption(String choice, String[] options) {\n        for (String option : options) {\n            if (option.equals(choice)) {\n                return true;\n            }\n        }\n        return false;\n    }\n\n    private static String askForStartingUnit(String unitCategory, String[] availableUnitsForCategory) {\n        String promptForStartingUnit = \"\\nWhat unit of \" + unitCategory + \" are you converting from?\";\n        String startingUnitType = askForOption(promptForStartingUnit, availableUnitsForCategory);\n        return startingUnitType;\n    }\n\n    private static double askForAmountOfStaringUnit(String unit) {\n        boolean isValidAmount;\n        double amount = 0;\n        do {\n            System.out.print(\"\\nEnter the amount of \" + unit + \" you need to convert from: \");\n            Scanner scanner = new Scanner(System.in);\n            try {\n                amount = scanner.nextDouble();\n                isValidAmount = true;\n\n            } catch (InputMismatchException e) {\n                System.out.print(\"\\nPlease enter the number only.\");\n                isValidAmount = false;\n            }\n        } while (isValidAmount);\n\n        return amount;\n    }\n\n    private static String askForEndingUnit(String unitCategory, String[] availableUnitsForCategory) {\n        String promptForEndingUnit = \"\\nWhat unit of \" + unitCategory + \" do you need to convert to?\";\n        String startingUnitType = askForOption(promptForEndingUnit, availableUnitsForCategory);\n        return startingUnitType;\n    }\n\n    private static String[] getAvailableUnitsForCategory(String unitCategory) {\n        if (unitCategory.toUpperCase().equals(\"LENGTH\")) {\n            return getLengthUnits();\n\n        } else if (unitCategory.toUpperCase().equals(\"TIME\")) {\n            return getTimeUnits();\n\n        } else if (unitCategory.toUpperCase().equals(\"TEMPERATURE\")) {\n            return getTemperatureUnits();\n\n        } else if (unitCategory.toUpperCase().equals(\"MASS\")) {\n            return getMassUnits();\n\n        } else {\n            printInvalidOptionError();\n            return new String[] {};\n        }\n    }\n\n    private static String[] getLengthUnits() {\n        return new String[] {\"METERS\", \"FEET\"};\n    }\n\n    private static String[] getTimeUnits() {\n        return new String[] {\"SECONDS\", \"MINUTES\"};\n    }\n\n    private static String[] getTemperatureUnits() {\n        return new String[] {\"CELSIUS\", \"FAHRENHEIT\"};\n    }\n\n    private static String[] getMassUnits() {\n        return new String[] {\"KILOGRAMS\", \"POUNDS\"};\n    }\n\n    private static double convert(String unitCategory, String startingUnit, double amountOfStartingUnit, String endingUnit) {\n        switch (unitCategory) {\n            case \"LENGTH\":\n                return convertForLength(startingUnit, amountOfStartingUnit, endingUnit);\n\n            case \"TIME\":\n                return convertForTime(startingUnit, amountOfStartingUnit, endingUnit);\n\n            case \"TEMPERATURE\":\n                return convertForTemperature(startingUnit, amountOfStartingUnit, endingUnit);\n\n            case \"MASS\":\n                return convertForMass(startingUnit, amountOfStartingUnit, endingUnit);\n\n            default:\n                printInvalidOptionError();\n                return 0;\n        }\n    }\n\n    private static double convertForLength(String startingUnit, double amountOfStartingUnit, String endingUnit) {\n        if (startingUnit.equals(\"METERS\") &amp;&amp; endingUnit.equals(\"FEET\")) {\n            return convertMetersToFeet(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(\"FEET\") &amp;&amp; endingUnit.equals(\"METERS\")) {\n            return convertFeetToMeters(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(endingUnit)) {\n            return amountOfStartingUnit;\n\n        } else {\n            printInvalidOptionError();\n            return 0;\n        }\n    }\n\n    private final static double FEET_PER_METER = 3.281;\n    private static double convertMetersToFeet(double meters) {\n        return meters * FEET_PER_METER;\n    }\n\n    private static double convertFeetToMeters(double feet) {\n        return feet \/ FEET_PER_METER;\n    }\n\n    private static double convertForTime(String startingUnit, double amountOfStartingUnit, String endingUnit) {\n        if (startingUnit.equals(\"SECONDS\") &amp;&amp; endingUnit.equals(\"MINUTES\")) {\n            return convertSecondsToMinutes(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(\"MINUTES\") &amp;&amp; endingUnit.equals(\"SECONDS\")) {\n            return convertMinutesToSeconds(amountOfStartingUnit);\n            \n        } else if (startingUnit.equals(endingUnit)) {\n            return amountOfStartingUnit;\n\n        } else {\n            printInvalidOptionError();\n            return 0;\n        }\n    }\n\n    private final static int SECONDS_PER_MINUTE = 60;\n    private static double convertSecondsToMinutes(double seconds) {\n        return seconds \/ SECONDS_PER_MINUTE;\n    }\n\n    private static double convertMinutesToSeconds(double minutes) {\n        return minutes * SECONDS_PER_MINUTE;\n    }\n\n    private static double convertForTemperature(String startingUnit, double amountOfStartingUnit, String endingUnit) {\n        if (startingUnit.equals(\"CELSIUS\") &amp;&amp; endingUnit.equals(\"FAHRENHEIT\")) {\n            return convertCelsiusToFahrenheit(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(\"FAHRENHEIT\") &amp;&amp; endingUnit.equals(\"CELSIUS\")) {\n            return convertFahrenheitToCelsius(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(endingUnit)) {\n            return amountOfStartingUnit;\n\n        } else {\n            printInvalidOptionError();\n            return 0;\n        }\n    }\n\n    private static double convertCelsiusToFahrenheit(double celsius) {\n        return (celsius * (9.0\/5.0)) + 32;\n    }\n\n    private static double convertFahrenheitToCelsius(double fahrenheit) {\n        return (fahrenheit - 32) * (5.0\/9.0);\n    }\n\n    private static double convertForMass(String startingUnit, double amountOfStartingUnit, String endingUnit) {\n        if (startingUnit.equals(\"KILOGRAMS\") &amp;&amp; endingUnit.equals(\"POUNDS\")) {\n            return convertKilogramsToPounds(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(\"POUNDS\") &amp;&amp; endingUnit.equals(\"KILOGRAMS\")) {\n            return convertPoundsToKilograms(amountOfStartingUnit);\n\n        } else if (startingUnit.equals(endingUnit)) {\n            return amountOfStartingUnit;\n\n        } else {\n            printInvalidOptionError();\n            return 0;\n        }\n    }\n\n    private final static double POUNDS_PER_KILOGRAM = 2.205;\n    private static double convertKilogramsToPounds(double kilograms) {\n        return kilograms \/ POUNDS_PER_KILOGRAM;\n    }\n\n    private static double convertPoundsToKilograms(double pounds) {\n        return pounds * POUNDS_PER_KILOGRAM;\n    }\n\n    private static void printResults(String startingUnit, double amountOfStartingUnit, String endingUnit, double amountOfEndingUnit) {\n        System.out.println(\"\\nResult: \" + amountOfStartingUnit + \" \" + startingUnit + \" equals \" +\n                amountOfEndingUnit + \" \" + endingUnit);\n    }\n\n    private static boolean askToRerunProgram() {\n        System.out.print(\"\\nWould you like to run the Unit Conversion Calculator again? (Y\/N): \");\n        Scanner scanner = new Scanner(System.in);\n        String userResponse = scanner.next().toUpperCase();\n        return userResponse.equals(\"Y\");\n    }\n\n    private static void printInvalidOptionError() {\n        System.out.println(\"\\nERROR!\");\n        System.out.println(\"An invalid option was selected. Please try again.\");\n    }\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>THIS BOOK IS STILL IN BETA STATE. If you&#8217;re interested in becoming a beta tester, please email me at adam@pragmaticways.com to request a free copy. Day 1 Exercises Hello World<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/pages\/619"}],"collection":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/comments?post=619"}],"version-history":[{"count":0,"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/pages\/619\/revisions"}],"wp:attachment":[{"href":"https:\/\/pragmaticways.com\/wp-json\/wp\/v2\/media?parent=619"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}