Lecture No. 05

Dated: 29-04-2025

using System;

class Booleans {
    public static void Main() {
        bool content = true;
        bool nocontent = false;
        Console.WriteLine("It is {0} that C# Station provides C# programming language content.", content);
        Console.WriteLine("The statement above is not {0}.", nocontent);
    }
}

Integer Types

Type	Size (in bits)	Range
sbyte	\(8\)	\(-128\) to \(127\)
byte	\(8\)	\(0\) to \(255\)
short	\(16\)	\(-32768\) to \(32767\)
ushort	\(16\)	\(0\) to \(65535\)
int	\(32\)	\(-2147483648\) to \(2147483647\)
uint	\(32\)	\(0\) to \(4294967295\)
long	\(64\)	\(-9223372036854775808\) to \(9223372036854775807\)
ulong	\(64\)	\(0\) to \(18446744073709551615\)
char	\(16\)	\(0\) to \(65535\)

Floating Types

Type	Size (in bits)	Precision	Range
float	\(32\)	\(7\) digits	\(1.5 \times 10^{-45}\) to \(3.4 \times 10^{38}\)
double	\(64\)	\(15\)-\(16\) digits	\(5.0 \times 10^{-324}\) to \(1.7 \times 10^{308}\)
decimal	\(128\)	\(28\)-\(29\) decimal places	\(1.0 \times 10^{-28}\) to \(7.9 \times 10^{28}\)

Escape Sequences

Char	Meaning	Value
\'	Single quote	0x0027
\"	Double quote	0x0022
\\	Backslash	0x005C
\0	Null	0x0000
\a	Alert	0x0007
\b	Backspace	0x0008
\f	Form feed	0x000C
\n	New line	0x000A
\r	Carriage return	0x000D
\t	Horizontal tab	0x0009
\v	Vertical tab	0x000B

Operators

Category(by precedence)	Operator(s)	Associativity
Primary	x.y, f(x), a[x], x++, x--, new, typeof, default, checked, unchecked, delegate	left
Unary	+, -, !, ~, ++x, --x, (T)x	right
Multiplicative	*, /, %	left
Additive	+, -	left
Shift	<<, >>	left
Relational	<, >, <=, >=, is, as	left
Equality	==, !=	right
Logical AND	&	left
Logical XOR	^	left
Logical OR	\|	left
Conditional AND	&&	left
Conditional OR	\|\|	left
Null Coalescing	??	left
Ternary	?:	right
Assignment	= *= /= %= += -= <<= >>= &= ^= \|=	right

Arrays

using System;

class Array {
    public static void Main() {
        int[] myints        = { 5, 10, 15 };
        bool[][] mybools    = new bool[2][];
        mybools[0]          = new bool[2];
        mybools[1]          = new bool[1];
        double[,] mydoubles = new double[2, 2];
        string[] mystrings  = new string[3];

        Console.WriteLine("myints[0]: {0}, myints[1]: {1}, myints[2]: {2}", myints[0], myints[1], myints[2]);

        mybools[0][0] = true;
        mybools[0][1] = false;
        mybools[1][0] = true;
        Console.WriteLine("mybools[0][0]: {0}, mybools[1][0]: {1}", mybools[0][0], mybools[1][0]);

        mydoubles[0, 0] = 3.147;
        mydoubles[0, 1] = 7.157;
        mydoubles[1, 1] = 2.117;
        mydoubles[1, 0] = 56.00138917;
        Console.WriteLine("mydoubles[0, 0]: {0}, mydoubles[1, 0]: {1}", mydoubles[0, 0], mydoubles[1, 0]);

        mystrings[0] = "Joe";
        mystrings[1] = "Matt";
        mystrings[2] = "Robert";
        Console.WriteLine("mystrings[0]: {0}, mystrings[1]: {1}, mystrings[2]: {2}", mystrings[0], mystrings[1], mystrings[2]);
    }
}

Loops

while

using System;

class whileloop {
    public static void Main() {
        int myint = 0;
        while (myint < 10)
        {
            Console.Write("{0} ", myint);
            myint++;
        }
        Console.WriteLine();
    }
}

for

using System;

class forloop {
    public static void Main() {
        for (int i = 0; i < 20; i++)
        {
            if (i == 10)
                break;
            if (i % 2 == 0)
                continue;
            Console.Write("{0} ", i);
        }
        Console.WriteLine();
    }
}

foreach

using System;

class foreachloop {
    public static void Main() {
        string[] names = { "Cheryl", "Joe", "Matt", "Robert" };
        foreach (string person in names)
        {
            Console.WriteLine("{0} ", person);
        }
    }
}

Methods

Syntax

Attributes modifiers return_type method_name(parameters) {statements}

using System;

class onemethod {
    public static void Main() {
        string mychoice;
        onemethod om = new onemethod();
        mychoice = om.getchoice();
    }

    string getchoice() {
        return "example";
    }
}