Module 2. Learning the C# Syntax

Working with Code Blocks and Statements

When debugging C# code, start from top of file to bottom. As some problems may result from previous error/warning

Adding Numbers and Creating Arrays

C# can use var for implicit typed local variable. It's optional to use var or specific data type. But C# is still strong type language.

C# error message: "Use of unassigned local variable 'number'" as C# does not allow array created w/o assignment. Can be fixed by variable creation using new with specified array length.

double[] numbers = new double[10];

Looping through Arrays

Array initialization syntax e.g.:

            var numbers = new double[3] {12.7, 10.3, 1.1};

can be further simplified, as C# compiler can deduct array variable type and length

var numbers = new[] {12.7, 10.3, 1.1};

To loop through each element in array, use foreach

            foreach (var number in numbers)
            {
                result += number;
            }

Using a List

Problem of array as data structure: fixed size during initialization.
Solution: Data structure List (extendable)

To create List object:

need using List namespace. e.g. using System.Collections.Generic;
need specify Type Parameters. e.g. List<double> grades; to specify object type within the list.
Initialize the List is also needed List<double> grades = new List<double>();
(Optional) we can initialize the list during creation List<double> grades = new List<double>() {12.7, 10.3, 6.11, 4.1};

Now we have a dynamic sized object to contain other variables

To use List:

Add element: grades.Add(56.1);
Index list: grades[2];