iterating through a collection containing different types of numericvalues and adding a specified nu

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=?ISO-8859-1?Q?Anders_W=FCrtz?=

i have an assignment to iterate through a collection containing
different types of numeric values (float, double, int, byte, short etc.)
and to add 1 to all of them. I tried with array and arraylist so far,
but i either get a cast exception or the value doesn't seem to get
updated at all. What should i be doing to make it work?

Thanks in advance

Anders
 
Anders said:
i have an assignment to iterate through a collection containing
different types of numeric values (float, double, int, byte, short etc.)
and to add 1 to all of them. I tried with array and arraylist so far,
but i either get a cast exception or the value doesn't seem to get
updated at all. What should i be doing to make it work?

Thanks in advance

Anders
Click to expand...

try this:

ArrayList al = new ArrayList();
al.Add((int)5);
al.Add((double)7.89);
al.Add((short)12);

foreach (object o in al)
{
if (o is int)
o = ((int)o)++;
else if (o is double)
o = ((double)o)++
<...etc...>
}

Hope it helps
MuZZy
 
Anders said:
i have an assignment to iterate through a collection containing
different types of numeric values (float, double, int, byte, short etc.)
and to add 1 to all of them. I tried with array and arraylist so far,
but i either get a cast exception or the value doesn't seem to get
updated at all. What should i be doing to make it work?

Thanks in advance
Click to expand...

There are lots of ways to do this, I'm not sure what they are teaching
you at present. If you *know* each one of them is a value type, you can
just convert them all to a given super-type (like double) and add to
them.
Otherwise, you could do something like this:

ArrayList a = new ArrayList();
int i = 1;
float f = 2.0f;
double d = 3.0;
byte b = 4;
string s = "hello";

// Add some data to the array.
a.Add( i );
a.Add( f );
a.Add( d );
a.Add( b );
a.Add( s );

// Print them out to show
foreach ( object o in a )
Console.Out.WriteLine("value: {0}", o );

// Increment those we can increment.
for ( int o=0; o<a.Count; ++o )
{
// Can't convert non-value types
if ( a[o].GetType().IsValueType )
{
// Make it a double
double d1 = (double)Convert.ChangeType( a[o], d.GetType() );
// Increment it
d1 += 1.0;
// Make it what it was.
object obj = Convert.ChangeType( d1, a[o].GetType() );
// And store it back in the array
a[o] = obj;
}
}

// Print them out to show
foreach ( object o in a )
Console.Out.WriteLine("value: {0}", o );

This isn't pretty and it isn't elegant. But it should get you started.

Matt
 
Anders said:
i have an assignment to iterate through a collection containing
different types of numeric values (float, double, int, byte, short etc.)
and to add 1 to all of them. I tried with array and arraylist so far,
but i either get a cast exception or the value doesn't seem to get
updated at all. What should i be doing to make it work?

Thanks in advance

Anders
Click to expand...
private ArrayList data;

......

this.byteField = 2;
this.shortField = 2;
this.intField = 2;
this.longField = 2;
this.sbyteField = 2;
this.ushortField = 2;
this.uintField = 2;
this.ulongField = 2;
this.floatField = 2;
this.doubleField = 2;
this.decimalField = 2;

data = new ArrayList();
data.Add(this.byteField);
data.Add(this.shortField);
data.Add(this.intField);
data.Add(this.longField);
data.Add(this.sbyteField);
data.Add(this.ushortField);
data.Add(this.uintField);
data.Add(this.ulongField);
data.Add(this.floatField);
data.Add(this.doubleField);
data.Add(this.decimalField);
....

in a method...

....

foreach (object o in data)
{
if (o is byte)
o = ((byte)o)++;
else if (o is double)
o = ((short)o)++;
else if (o is int)
o = ((int)o)++;
else if (o is long)
o = ((long)o)++;
else if (o is sbyte)
o = ((sbyte)o)++;
else if (o is ushort)
o = ((ushort)o)++;
else if (o is uint)
o = ((uint)o)++;
else if (o is ulong)
o = ((ulong)o)++;
else if (o is float)
o = ((float)o)++;
else if (o is double)
o = ((double)o)++;
else if (o is decimal)
o = ((decimal)o)++;
}

compiler errors:

1. cannot assign to 'o' because it is read-only
2. The left-hand side of an assignment must be a variable,
property or indexer

how do i solve this so 1 is added to all the values?

thanks in advance

Anders
 
MuZZy said:
try this:

ArrayList al = new ArrayList();
al.Add((int)5);
al.Add((double)7.89);
al.Add((short)12);

foreach (object o in al)
{
if (o is int)
o = ((int)o)++;
else if (o is double)
o = ((double)o)++
<...etc...>
}

Hope it helps
MuZZy
Click to expand...

private ArrayList data;

......

this.byteField = 2;
this.shortField = 2;
this.intField = 2;
this.longField = 2;
this.sbyteField = 2;
this.ushortField = 2;
this.uintField = 2;
this.ulongField = 2;
this.floatField = 2;
this.doubleField = 2;
this.decimalField = 2;

data = new ArrayList();
data.Add(this.byteField);
data.Add(this.shortField);
data.Add(this.intField);
data.Add(this.longField);
data.Add(this.sbyteField);
data.Add(this.ushortField);
data.Add(this.uintField);
data.Add(this.ulongField);
data.Add(this.floatField);
data.Add(this.doubleField);
data.Add(this.decimalField);
....

in a method...

....

foreach (object o in data)
{
if (o is byte)
o = ((byte)o)++;
else if (o is double)
o = ((short)o)++;
else if (o is int)
o = ((int)o)++;
else if (o is long)
o = ((long)o)++;
else if (o is sbyte)
o = ((sbyte)o)++;
else if (o is ushort)
o = ((ushort)o)++;
else if (o is uint)
o = ((uint)o)++;
else if (o is ulong)
o = ((ulong)o)++;
else if (o is float)
o = ((float)o)++;
else if (o is double)
o = ((double)o)++;
else if (o is decimal)
o = ((decimal)o)++;
}

compiler errors:

1. cannot assign to 'o' because it is read-only
2. The left-hand side of an assignment must be a
variable, property or indexer

how do i solve this so 1 is added to all the values?

thanks in advance

Anders
 
Anders said:
private ArrayList data;

......

this.byteField = 2;
this.shortField = 2;
this.intField = 2;
this.longField = 2;
this.sbyteField = 2;
this.ushortField = 2;
this.uintField = 2;
this.ulongField = 2;
this.floatField = 2;
this.doubleField = 2;
this.decimalField = 2;

data = new ArrayList();
data.Add(this.byteField);
data.Add(this.shortField);
data.Add(this.intField);
data.Add(this.longField);
data.Add(this.sbyteField);
data.Add(this.ushortField);
data.Add(this.uintField);
data.Add(this.ulongField);
data.Add(this.floatField);
data.Add(this.doubleField);
data.Add(this.decimalField);
....

in a method...

....

foreach (object o in data)
{
if (o is byte)
o = ((byte)o)++;
Click to expand...

Nope, can't do that. The object itself isn't modifiable.
You'd have to do something like this:

ArrayList data = new ArrayList();
data.Add(byteField);
data.Add(shortField);
data.Add(intField);

for (int i=0; i<data.Count; ++i )
{
object o = data;
if (o is byte)
{
byte b = (byte)o;
b++;
data = b;
}
}


Matt
 
foreach is a readonly implementation you cannot change the object.
Just use for loop it will work fine

Saurabh
private ArrayList data;

......

this.byteField = 2;
this.shortField = 2;
this.intField = 2;
this.longField = 2;
this.sbyteField = 2;
this.ushortField = 2;
this.uintField = 2;
this.ulongField = 2;
this.floatField = 2;
this.doubleField = 2;
this.decimalField = 2;

data = new ArrayList();
data.Add(this.byteField);
data.Add(this.shortField);
data.Add(this.intField);
data.Add(this.longField);
data.Add(this.sbyteField);
data.Add(this.ushortField);
data.Add(this.uintField);
data.Add(this.ulongField);
data.Add(this.floatField);
data.Add(this.doubleField);
data.Add(this.decimalField);
....

in a method...

....

foreach (object o in data)
{
if (o is byte)
o = ((byte)o)++;
Click to expand...

Nope, can't do that. The object itself isn't modifiable.
You'd have to do something like this:

ArrayList data = new ArrayList();
data.Add(byteField);
data.Add(shortField);
data.Add(intField);

for (int i=0; i<data.Count; ++i )
{
object o = data;
if (o is byte)
{
byte b = (byte)o;
b++;
data = b;
}
}


Matt
 

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