1. Correctly Formatting the Source Code Svetlin Nakov Telerik Software Academy academy.telerik.com

2. 1. Why Do We Need Code Formatting? 2. Formatting Methods 3. Formatting Types 4. Common Mistakes 5. Alignments 6. Recommended Practices 2

3. Why Do We Need It?

4. 4 public const string FILE_NAME ="example.bin" ; static void Main ( ){ FileStream fs= new FileStream(FILE_NAME,FileMode. CreateNew) // Create the writer for data. ;BinaryWriter w=new BinaryWriter ( fs );// Write data to Test.data. for( int i=0;i<11;i++){w.Write((int)i);}w.Close(); fs. Close ( ) // Create the reader for data. ;fs=new FileStream(FILE_NAME,FileMode. Open, FileAccess.Read) ;BinaryReader r = new BinaryReader(fs); // Read data from Test.data. for (int i = 0; i < 11; i++){ Console.WriteLine for (int i = 0; i < 11; i++){ Console.WriteLine (r.ReadInt32 ()) ;}r. Close ( ); fs. Close ( ) ; }

5.  Good formatting goals  To improve code readability  To improve code maintainability  Fundamental principle of code formatting:  Any formatting style that follows the above principle is good  Any other formatting is not good 5 The formating of the source code should disclose its logical structure.

6.  Put { and } alone on a line under the corresponding parent block  Indent the block contents by a single [Tab]  Don't indent with spaces  Example: 6 if (some condition) { // Block contents indented by a single [Tab] // Block contents indented by a single [Tab] // Don't use spaces for indentation // Don't use spaces for indentation}

7.  Put { at the end of the block and } alone on a line under the corresponding parent block  Indent the block contents by a single [Tab]  Don't indent with spaces  Example: 7 if (some condition) { // Block contents indented by a single [Tab] // Block contents indented by a single [Tab] // Don't use spaces for indentation // Don't use spaces for indentation}

8.  Use empty line for separation between methods: 8 public class Factorial { private static ulong CalcFactorial(uint num) private static ulong CalcFactorial(uint num) { if (num == 0) if (num == 0) return 1; return 1; else else return num * CalcFactorial(num - 1); return num * CalcFactorial(num - 1); } static void Main() static void Main() { ulong factorial = CalcFactorial(5); ulong factorial = CalcFactorial(5); Console.WriteLine(factorial); Console.WriteLine(factorial); }} Leave empty line between methods Always use { and } after if (there is no space to do it here)

9.  Methods should be indented with a single [Tab] from the class body  Methods body should be indented with a single [Tab] as well 9 public class IndentationExample { private int Zero() private int Zero() { return 0; return 0; }} The entire method is indented with a single [Tab] Method body is also indented

10.  Brackets in the method declaration should be formatted as follows:  Don't use spaces between the brackets:  The same applies for if -conditions and for - loops: 10 private static ulong CalcFactorial(uint num) if (condition) { … }

11.  Separate method parameters by comma followed by a space  Don't put comma before the space  Examples:  Incorrect examples: 11 private void RegisterUser(string username, string password) RegisterUser("nakov", "s3cr3t!p@ssw0rd");

12.  Use an empty line to separate logically related sequences of lines: 12 private List PrepareReports() { List reports = new List (); List reports = new List (); // Create incomes reports // Create incomes reports Report incomesSalesReport = PrepareIncomesSalesReport(); Report incomesSalesReport = PrepareIncomesSalesReport(); reports.Add(incomesSalesReport); reports.Add(incomesSalesReport); Report incomesSupportReport = PrepareIncomesSupportReport(); Report incomesSupportReport = PrepareIncomesSupportReport(); reports.Add(incomesSupportReport); reports.Add(incomesSupportReport); // Create expenses reports // Create expenses reports Report expensesPayrollReport = PrepareExpensesPayrollReport(); Report expensesPayrollReport = PrepareExpensesPayrollReport(); reports.Add(expensesPayrollReport); reports.Add(expensesPayrollReport); Report expensesMarketingReport = PrepareExpensesMarketingReport(); Report expensesMarketingReport = PrepareExpensesMarketingReport(); reports.Add(expensesMarketingReport); reports.Add(expensesMarketingReport); return reports; return reports;} Empty line

13.  Formatting classes / structures / interfaces / enumerations  Indent the class body with a single [Tab]  Use the following order of definitions:  Constants, delegates, inner types, fields, constructors, properties, methods  Static members, public members, protected members, internal members, private members  The above order of definitions is not the only possible correct one 13

14. 14 public class Dog { // Static variables // Static variables public const string SPECIES = public const string SPECIES = "Canis Lupus Familiaris"; "Canis Lupus Familiaris"; // Instance variables // Instance variables private int age; private int age; // Constructors // Constructors public Dog(string name, int age) public Dog(string name, int age) { this.Name = name; this.Name = name; this.age = age; this.age = age; } (continues on the next slide)

15. 15 // Properties // Properties public string Name { get; set; } public string Name { get; set; } // Methods // Methods public void Breath() public void Breath() { // TODO: breathing process // TODO: breathing process } public void Bark() public void Bark() { Console.WriteLine("wow-wow"); Console.WriteLine("wow-wow"); }}

16. 16 public class Dog { // Static variables // Static variables public static final string SPECIES = public static final string SPECIES = "Canis Lupus Familiaris"; "Canis Lupus Familiaris"; // Instance variables // Instance variables private int age; private int age; // Constructors // Constructors public Dog(String name, int age) { public Dog(String name, int age) { this.setName(name); this.setName(name); this.setAge(age); this.setAge(age); } // Properties // Properties public String getName() { return this.name } public String getName() { return this.name } …

17.  Formatting conditional statements and loops  Always use { } block after if / for / while, even when a single operator follows  Indent the block body after if / for / while  Never put the block after if / for / while on the same line!  Always put the { on the next line (in C#)  Always put the { on the same line (in Java)  Never indent with more than one [Tab] 17

18.  Example:  Incorrect examples: 18 for (int i=0; i<10; i++) { Console.WriteLine("i={0}", i); Console.WriteLine("i={0}", i);} for (int i=0; i<10; i++) Console.WriteLine("i={0}", i); Console.WriteLine("i={0}", i); for (int i=0; i<10; i++) Console.WriteLine("i={0}", i); for (int i=0; i<10; i++) { Console.WriteLine("i={0}", i); Console.WriteLine("i={0}", i);} The { and } are missing Never put multiple stetements on the same line! In C# the { should be on the next line

19.  Empty lines are used to separate logically unrelated parts of the source code  Don't put empty lines when not needed! 19 public static void PrintList(List ints) { Console.Write("{ "); Console.Write("{ "); foreach (int item in ints) foreach (int item in ints) { Console.Write(item); Console.Write(item); Console.Write(" "); Console.Write(" "); } Console.WriteLine("}"); Console.WriteLine("}");} static void Main() { // … // … An empty line separates the methods

20. 20 public static void PrintList(List ints) { Console.Write("{ "); Console.Write("{ "); foreach (int item in ints) foreach (int item in ints) { Console.Write(item); Console.Write(item); Console.Write(" "); Console.Write(" "); } Console.WriteLine("}"); Console.WriteLine("}");} static void Main() { //... //...} What do these empty lines server for?

21.  Break long lines after punctuation  Indent the second line by single [Tab]  Do not additionally indent the third line  Examples: 21 DictionaryEntry newEntry = new DictionaryEntry ( new DictionaryEntry ( oldEntry.Key, oldEntry.Value); oldEntry.Key, oldEntry.Value); if (matrix[x, y] == 0 || matrix[x-1, y] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x, y+1] == 0) matrix[x, y+1] == 0) { …

22. 22 if (matrix[x, y] == 0 || matrix[x-1, y] == 0 || matrix[x+1, y] == 0 || matrix[x, 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x, y+1] == 0) y-1] == 0 || matrix[x, y+1] == 0) { … if (matrix[x, y] == 0 || matrix[x-1, y] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x, y+1] == 0) matrix[x, y+1] == 0) { … DictionaryEntry newEntry = new DictionaryEntry (oldEntry = new DictionaryEntry (oldEntry.Key, oldEntry.Value);.Key, oldEntry.Value);

23.  In C# use single [Tab] after breaking a long line:  In Java use double [Tab] in the carried long lines: 23 if (matrix[x, y] == 0 || matrix[x-1, y] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x, y+1] == 0) matrix[x, y+1] == 0){ matrix[x, y] == 1; matrix[x, y] == 1;} if (matrix[x, y] == 0 || matrix[x-1, y] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x, y+1] == 0) { matrix[x, y+1] == 0) { matrix[x, y] == 1; matrix[x, y] == 1;}

24.  All types of alignments are considered harmful  Alignments are hard-to-maintain!  Incorrect examples: 24 int count = 0; DateTime date = DateTine.Now.Date; Student student = new Student(); List students = new List (); matrix[x, y] == 0; matrix[x + 1, y + 1] == 0; matrix[2 * x + y, 2 * y + x] == 0; matrix[x * y, x * y] == 0; Think about renaming Student to SchoolStudent

25.  Break long lines after punctuation  Indent the second line by single [Tab]  Do not additionally indent the third line  Examples: 25 DictionaryEntry newEntry = new DictionaryEntry ( new DictionaryEntry ( oldEntry.Key, oldEntry.Value); oldEntry.Key, oldEntry.Value); if (matrix[x, y] == 0 || matrix[x-1, y] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x+1, y] == 0 || matrix[x, y-1] == 0 || matrix[x, y+1] == 0) matrix[x, y+1] == 0) { …

26.  Take advantage of your IDE to help formatting the code [Shift+Ctrl+F]  Automatic alignment  Indentation  Style Code analysis  Visual Studio – StyleCop  http://code.msdn.microsoft.com/sourceanalysis http://code.msdn.microsoft.com/sourceanalysis  Eclipse – CheckStyle  http://sourceforge.net/projects/eclipse-cs/ http://sourceforge.net/projects/eclipse-cs/ 26

27. Questions?Questions? http://academy.telerik.com

28. 1. Format correctly the following source code:  C# code given in the file events.cs.  Java code given in the file BASE64.java.  PHP code given in the file utils.php.  Use the official code conventions for C# / Java / PHP:  Official C# Coding Conventions (MSDN) Official C# Coding Conventions (MSDN) Official C# Coding Conventions (MSDN)  Official Java Code Conventions (by Oracle) Official Java Code Conventions (by Oracle) Official Java Code Conventions (by Oracle)  Zend code convention for PHP Zend code convention for PHP Zend code convention for PHP 28