Core C# and .NET
Quick Reference
1. Data Types
Primitive
Size
Example
string
2 bytes/char
s = “reference”;
bool
b = true;
char
2 bytes
ch = ‘a’;
byte
1 byte
b = 0x78;
short
2 bytes
Ival = 54;
int
4 bytes
Ival = 540;
long
8 bytes
ival = 5400;
float
4 bytes
val = 54.0F;
double
8 bytes
val = 54.0D;
decimal
16 bytes
val = 54.0M;
2. Arrays
Declaration
int[] numArray = {1903, 1907, 1910};
int[] numArray = new int[3];
// 3 rows and 2 columns
int[ , ] nums = {{1907, 1990}, {1904, 1986}, {1910, 1980}};
Array Operations
Array.Sort(numArray); // sort ascending
// Sort begins at element 4 and sorts 10 elements
Array.Sort(numArray, 4,10);
// Use one array as a key and sort two arrays
string[] values = {“Cary”, “Gary”, “Barbara”};
string[] keys = {“Grant”, “Cooper”, “Stanwyck”};
Array.Sort(keys, values);
// Clear elements in array (array, 1st element, # elements)
Array.Clear(numArray, 0, numArray.Length);
// Copy elements from one array to another
Array.Copy(src, target, numelements);
3. String Operations
Method
Description
Compare
String.Compare(stra, strb, case, ci)
bool case – true for case insensitive
ci – new CultureInfo(“en-US”)
returns: <0 if a<b, 0 if a=b, 1 if a>b
IndexOf
str.IndexOf(val, start, num)
val – string to search for
start – where to begin in string
num – number of chars to search
returns (–1) if no match.
LastIndexOf Search from end of string.
Replace
newstr= oldstr.Replace(“old”,”new”);
Split
Char[] delim= {‘ ‘, ‘,’};
string w = “Kim, Joanna Leslie”;
// create array with three names
string[] names= w.Split(delim);
6. Formatting Numeric and Date Values
Format Item Syntax: {index[,alignment] [:format string]}
index – Specifies element in list of values to which format is applied.
alignment – Indicates minimum width (in characters) to display value.
format string – Contains the code that specifies the form