Variables

Naming#

Variable names should be concise and representative of nature and the quantity of the value it holds or will potentially hold.

Names#

Do

var student = new Student();

Don't

var s = new Student();

Also, Don't

var stdnt = new Student();

The same rule applies to lambda expressions:

Do

students.Where(student => student ... );

Don't

students.Where(s => s ... );

Plurals#

Do

var students = new List<Student>();

Don't

var studentList = new List<Student>();

Names with Types#

Do

var student = new Student();

Don't

var studentModel = new Student();

Also, Don't

var studentObj = new Student();

Nulls or Defaults#

If a variable value is its default such as 0 for int or null for strings and you are not planning on changing that value (for testing purposes for instance) then the name should identify that value.

Do

Student noStudent = null;

Don't

Student student = null;

Also, Do

int noChangeCount = 0;

But, Don't

int changeCount = 0;

Declarations#

Declaring a variable and instantiating it should indicate the immediate type of the variable, even if the value is to be determined later.

Clear Types#

If the right side type is clear, then use var to declare your variable

Do

var student = new Student();

Don't

Student student = new Student();

Semi-Clear Types#

If the right side isn’t clear (but known) of the returned value type, then you must explicitly declare your variable with its type.

Do

Student student = GetStudent();

Don't

var student = GetStudent();

Unclear Types#

If the right side isn’t clear and unknown (such as an anonymous types) of the returned value type, you may use var as your variable type.

Do

var student = new
{
    Name = "Hassan",
    Score = 100
};

Single-Property Types#

Assign properties directly if you are declaring a type with one property.

Do

var inputStudentEvent = new StudentEvent();
inputStudentEvent.Student = inputProcessedStudent;

Don't

var inputStudentEvent = new StudentEvent
{
    Student = inputProcessedStudent
};

Also, Do

var studentEvent = new StudentEvent
{
    Student = someStudent,
    Date = someDate
};

Don't

var studentEvent = new StudentEvent();
studentEvent.Student = someStudent;
studentEvent.Date = someDate;

Organization#

Breakdown#

If a variable declaration exceeds 120 characters, break it down starting from the equal sign.

Do

List<Student> washingtonSchoolsStudentsWithGrades = 
    await GetAllWashingtonSchoolsStudentsWithTheirGradesAsync();

Don't

List<Student> washingtonSchoolsStudentsWithGrades = await GetAllWashingtonSchoolsStudentsWithTheirGradesAsync();

Multiple Declarations#

Declarations that occupy two lines or more should have a new line before and after them to separate them from previous and next variables declarations.

Do

Student student = GetStudent();

List<Student> washingtonSchoolsStudentsWithGrades = 
    await GetAllWashingtonSchoolsStudentsWithTheirGradesAsync();

School school = await GetSchoolAsync();

Don't

Student student = GetStudent();
List<Student> washingtonSchoolsStudentsWithGrades = 
    await GetAllWashingtonSchoolsStudentsWithTheirGradesAsync();
School school = await GetSchoolAsync();

Also, declarations of variables that are of only one line should have no new lines between them.

Do

Student student = GetStudent();
School school = await GetSchoolAsync();

Don't

Student student = GetStudent();

School school = await GetSchoolAsync();