Declaring variables within FOR loops

for (int i =0; i< 10; i++)
{
    decimal? testDecimal;
    string testString;

    switch( i % 2  )
    {
        case 0:
        testDecimal = i / ( decimal ).32;
        testString = i.ToString();
            break;
        default:
            testDecimal = null;
            testString = null;
            break;
    }

    Console.WriteLine( "Loop {0}: testDecimal={1} - testString={2}", i, testDecimal , testString );
}

int value;
        for (int i = 0; i < 5; i++)
        {
            value = i;
            ThreadPool.QueueUserWorkItem(delegate { Console.WriteLine(value); });
        }
        Console.ReadLine();

for (int i = 0; i < 5; i++)
        {
            int value = i;
            ThreadPool.QueueUserWorkItem(delegate { Console.WriteLine(value); });
        }
        Console.ReadLine();

using System;

class A
{
    public static void Main()
    {
        for (int i =0; i< 10; i++)
        {
            decimal? testDecimal;
            string testString;
            switch( i % 2  )
            {
                case 0:
                    testDecimal = i / ( decimal ).32;
                    testString = i.ToString();
                    break;
                default:
                    testDecimal = null;
                    testString = null;
                    break;
            }

            Console.WriteLine( "Loop {0}: testDecimal={1} - testString={2}", i, testDecimal , testString );
        }
    }
}

.method public hidebysig static void Main() cil managed
{
    .entrypoint
    .maxstack 8
    .locals init (
        [0] int32 num,
        [1] valuetype [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal> nullable,
        [2] string str,
        [3] int32 num2,
        [4] bool flag)
    L_0000: nop
    L_0001: ldc.i4.0
    L_0002: stloc.0
    L_0003: br.s L_0061
    L_0005: nop
    L_0006: ldloc.0
    L_0007: ldc.i4.2
    L_0008: rem
    L_0009: stloc.3
    L_000a: ldloc.3
    L_000b: ldc.i4.0
    L_000c: beq.s L_0010
    L_000e: br.s L_0038
    L_0010: ldloca.s nullable
    L_0012: ldloc.0
    L_0013: call valuetype [mscorlib]System.Decimal [mscorlib]System.Decimal::op_Implicit(int32)
    L_0018: ldc.i4.s 0x20
    L_001a: ldc.i4.0
    L_001b: ldc.i4.0
    L_001c: ldc.i4.0
    L_001d: ldc.i4.2
    L_001e: newobj instance void [mscorlib]System.Decimal::.ctor(int32, int32, int32, bool, uint8)
    L_0023: call valuetype [mscorlib]System.Decimal [mscorlib]System.Decimal::op_Division(valuetype [mscorlib]System.Decimal, valuetype [mscorlib]System.Decimal)
    L_0028: call instance void [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal>::.ctor(!0)
    L_002d: nop
    L_002e: ldloca.s num
    L_0030: call instance string [mscorlib]System.Int32::ToString()
    L_0035: stloc.2
    L_0036: br.s L_0044
    L_0038: ldloca.s nullable
    L_003a: initobj [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal>
    L_0040: ldnull
    L_0041: stloc.2
    L_0042: br.s L_0044
    L_0044: ldstr "Loop {0}: testDecimal={1} - testString={2}"
    L_0049: ldloc.0
    L_004a: box int32
    L_004f: ldloc.1
    L_0050: box [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal>
    L_0055: ldloc.2
    L_0056: call void [mscorlib]System.Console::WriteLine(string, object, object, object)
    L_005b: nop
    L_005c: nop
    L_005d: ldloc.0
    L_005e: ldc.i4.1
    L_005f: add
    L_0060: stloc.0
    L_0061: ldloc.0
    L_0062: ldc.i4.s 10
    L_0064: clt
    L_0066: stloc.s flag
    L_0068: ldloc.s flag
    L_006a: brtrue.s L_0005
    L_006c: ret
}

using System;

class A
{
    public static void Main()
    {
        decimal? testDecimal;
        string testString;

        for (int i =0; i< 10; i++)
        {
            switch( i % 2  )
            {
                case 0:
                    testDecimal = i / ( decimal ).32;
                    testString = i.ToString();
                    break;
                default:
                    testDecimal = null;
                    testString = null;
                    break;
            }

            Console.WriteLine( "Loop {0}: testDecimal={1} - testString={2}", i, testDecimal , testString );
        }
    }
}

.method public hidebysig static void Main() cil managed
{
    .entrypoint
    .maxstack 8
    .locals init (
        [0] valuetype [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal> nullable,
        [1] string str,
        [2] int32 num,
        [3] int32 num2,
        [4] bool flag)
    L_0000: nop
    L_0001: ldc.i4.0
    L_0002: stloc.2
    L_0003: br.s L_0061
    L_0005: nop
    L_0006: ldloc.2
    L_0007: ldc.i4.2
    L_0008: rem
    L_0009: stloc.3
    L_000a: ldloc.3
    L_000b: ldc.i4.0
    L_000c: beq.s L_0010
    L_000e: br.s L_0038
    L_0010: ldloca.s nullable
    L_0012: ldloc.2
    L_0013: call valuetype [mscorlib]System.Decimal [mscorlib]System.Decimal::op_Implicit(int32)
    L_0018: ldc.i4.s 0x20
    L_001a: ldc.i4.0
    L_001b: ldc.i4.0
    L_001c: ldc.i4.0
    L_001d: ldc.i4.2
    L_001e: newobj instance void [mscorlib]System.Decimal::.ctor(int32, int32, int32, bool, uint8)
    L_0023: call valuetype [mscorlib]System.Decimal [mscorlib]System.Decimal::op_Division(valuetype [mscorlib]System.Decimal, valuetype [mscorlib]System.Decimal)
    L_0028: call instance void [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal>::.ctor(!0)
    L_002d: nop
    L_002e: ldloca.s num
    L_0030: call instance string [mscorlib]System.Int32::ToString()
    L_0035: stloc.1
    L_0036: br.s L_0044
    L_0038: ldloca.s nullable
    L_003a: initobj [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal>
    L_0040: ldnull
    L_0041: stloc.1
    L_0042: br.s L_0044
    L_0044: ldstr "Loop {0}: testDecimal={1} - testString={2}"
    L_0049: ldloc.2
    L_004a: box int32
    L_004f: ldloc.0
    L_0050: box [mscorlib]System.Nullable`1<valuetype [mscorlib]System.Decimal>
    L_0055: ldloc.1
    L_0056: call void [mscorlib]System.Console::WriteLine(string, object, object, object)
    L_005b: nop
    L_005c: nop
    L_005d: ldloc.2
    L_005e: ldc.i4.1
    L_005f: add
    L_0060: stloc.2
    L_0061: ldloc.2
    L_0062: ldc.i4.s 10
    L_0064: clt
    L_0066: stloc.s flag
    L_0068: ldloc.s flag
    L_006a: brtrue.s L_0005
    L_006c: ret
}

Loop 0: testDecimal=0 - testString=0
Loop 1: testDecimal= - testString=
Loop 2: testDecimal=6.25 - testString=2
Loop 3: testDecimal= - testString=
Loop 4: testDecimal=12.5 - testString=4
Loop 5: testDecimal= - testString=
Loop 6: testDecimal=18.75 - testString=6
Loop 7: testDecimal= - testString=
Loop 8: testDecimal=25 - testString=8
Loop 9: testDecimal= - testString=

private void LoopTest()
{
    for (int i =0; i< 10; i++)
    {
        DoWork(i);
    }
}

private void Work(int i)
{
    decimal? testDecimal;
    string testString;

    switch (i % 2)
    {
        case 0:
            testDecimal = i / (decimal).32;
            testString = i.ToString();
            break;
        default:
            testDecimal = null;
            testString = null;
            break;
    }
    Console.WriteLine( "Loop {0}: testDecimal={1} - testString={2}", i, testDecimal , testString );
}

decimal? testDecimal;
string testString;

for (int i =0; i< 10; i++)
{
    switch( i % 2  )
    {
        case 0:
           testDecimal = i / ( decimal ).32;
           testString = i.ToString();
           Console.WriteLine( "Loop {0}: testDecimal={1} - testString={2}", i, testDecimal , testString );
            testDecimal = null;
            testString = String.Empty;
            break;
        default:
            testDecimal = null;
            testString = String.Empty;
            break;
    }

}