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Richard MacCutchan wrote: myJaggedArray.GetLength(0);
either my book doesn't cover this method you're using or it did and I forgot and I have to go back and read it, I know your buddies book probably covers that, I will read it later…
One other thing, you start talking about two-dimensional arrays and then you post in your code a jagged array.
Jagged Array
int [][]
Two-dimensional Array
int [,]
Right?
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WidmarkRob wrote: Right?
Excactly so; I was merely trying to illustrate how to look at the 'shape' of an array that has only two dimensions. Thinking about it in terms of rows and columns has always helped me when working with arrays.
Use the best guess
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I don't know if you had seen what my drill/exercise was supposed to be… I'm willing to bet a case of beer you be able to figure it out by looking at what I wrote…
I wrote it out the long and hard way… Only because at first, I couldn't quite figure out how to incorporate the for loop.
using System;
using System.Text;
namespace Two_Dimensional_Array
{
class Program
{
static void Main(string[] args)
{
string[,] grades = { { "Pass", "Good", "VeryGood", "Distinct" }, { "55%", "65%", "75%", "85%" } };
string[] gradeScore = {"Grade=", "Score="};
Console.WriteLine(gradeScore[0] + grades[0, 0] + " " + gradeScore[1] + grades[1, 0]);
Console.WriteLine(gradeScore[0] + grades[0, 1] + " " + gradeScore[1] + grades[1, 1]);
Console.WriteLine(gradeScore[0] + grades[0, 2] + " " + gradeScore[1] + grades[1, 2]);
Console.WriteLine(gradeScore[0] + grades[0, 3] + " " + gradeScore[1] + grades[1, 3]);
Console.Read();
}
}
}
After fiddling around with it for a couple of days, I was able to get the for loop in… But, as you'll notice from the code above… The first two lines that print to the screen are spaced out just a little bit further so the Score column is all lined up just like the way they wanted in the book.
Is there some sort of extra C# technique/trick to have the columns line up?
using System;
namespace Two_Dimensional_Array
{
class Program
{
static void Main(string[] args)
{
string[,] grades = { { "Pass", "Good", "VeryGood", "Distinct" }, { "55%", "65%", "75%", "85%" } };
string[] gradeScore = {"Grade=", "Score="};
for (int a = 0; a < 4; a++)
{
Console.WriteLine(gradeScore[0] + grades[0, a] + " " + gradeScore[1] + grades[1, a]);
}
Console.Read();
}
}
}
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WidmarkRob wrote: Is there some sort of extra C# technique/trick to have the columns line up?
Yes, it's all provided by the use of format strings[^], which allow you to specify the width of a field and the alignment of its content. There are also standard shorthand format notations for date, time, currency etc, or you can create your own. So you could code something like:
Console.WriteLine("{0}{1,-8} : {2}{3}", gradeScore[0], grades[0, a], gradeScore[1], grades[1, a]);
Console.WriteLine("Grade={0,-8} : Score={1}", grades[0, a], grades[1, a]);
Use the best guess
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This is one thing C++ programmers must learn really well or you start to run into trouble. C# has taken the dangerous stuff away, but it's now so simple that programmers don't understand what's going on, and when the details matter, it's often tricky because those details are hidden from you.
So, I don't know if this will be helpful or not, but looking at arrays at the low level always helped me...
int x[5];
That's a single-dimensional array - in C++ it's just 5 memory locations (0000-0004) containing int VALUES.
int x[5][5];
That's a two-dimensional array, but it's still LINEAR in memory - it's 25 integers in a row (0000-0024) (note: I'm using decimal memory addresses here for simplicity)
int x[5][];
This is where it gets tricky - that initializes 5 pointers, which point to integer arrays which aren't initialized yet. We have to initialize them, so if we did this...
x[0] = new int[5];
x[1] = new int[2];
....etc...
Now, in x[0] we have a pointer, pointing to a (probably distant) memory location of 5 integers, same as the array in the first example (and x[1] points to a 2-element array). Our x array contains pointers to those other arrays. THAT is a jagged array (x is, not the arrays x points to). See the difference now between the two-dimensional and jagged? A two-dimensional array is just a continuous block of memory with a clever way of indexing it, and that block holds the actual values. A jagged array holds no values, only pointers to other arrays.
And, C++ allows us to do this...
int x[5][5];
x[22] = 42;
....which sets the value "42" in the 23rd element of the array, which is the same as element [4][2] (the third "column" of the 5th "row")
Confused yet?
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I'm not trying to learn C++
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Never the less, you are using a computer, and what I just said there is how a computer works. Understanding what I said there will help you understand C#, which takes what I said and wraps a complicated memory manager around all that. But at the low levels, C# is creating pointers and memory blocks and sticking values in there, and when you say "int x[5];" that is exactly what is happening in C#.
Look at my first paragraph - C# is insulating you from the details which could help you understand arrays.
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if it'll make you feel any better, here is what I'm supposed to bring to the screen:
Grade=Pass Score=55%
Grade=Good Score=65%
Grade=VeryGood Score=75%
Grade=Distinct Score=85%
Drill 4-3
Display the contents of the two-dimensional array called “grades”
that was discussed in this section. Make sure you get the following
result:
I'm not taking any formal classes, but… This is a Drill/Exercise from an e-book I'm reading on C#
I will post my code and ask you fine people for input/feedback about how I did it and maybe how I could have done better…
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Oh, cool 
Please post the link to the e-book you are using, so we can see the context a little better.
My example wasn't about teaching C++, it was about understanding what the computer does when you put certain instructions in C# and the low-level differences between the types of arrays. C# hides those details from you, so you can be more productive, but it reduces understanding. Understanding those low-level concepts can prevent you from creating performance and memory problems in your programs.
Ever wonder why Windows takes twice as much memory to do half as much stuff as Linux? This is why.
EDIT: This is one of the best questions we've got in a long time. I get tired of the "plz snd codez" questions.
modified 20-May-13 17:26pm.
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WidmarkRob wrote: I'm not a script kiddie trying to find an easy way out…
Yeah I respect that. It's kinda why I thought you might be receptive to the low-level explanation of what's going on with this. Many people just want to get their assignment done and don't care how well it comes out, and those people create a lot of problems in the industry. I do my best to try to not create any more folks like that, who can produce miles and miles of bad code, that works. My production environment is acting very funny today because of code like that.
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the book I'm reading is very similar to this book:
http://www.charlespetzold.com/dotnet/
they are both nicely detailed and start out very similar, talking about the .net framework and a little history behind C#… How it took some of the concepts C and C++…
I'm going to read that other book, when I'm done reading the book that I paid for… 
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Everything he writes is good. I lived that history and it is fascinating. C# (and Java and other "managed" languages) solves a lot of the problems that C++ had where simple coding mistakes could lead to memory leaks and security problems. In C#, a lot of those coding mistakes just won't compile... like this...
if (x = y) {
}
In C++ that was an "assignment and test" all in one line. It assigns the value of y to x and casts the whole expression to boolean, so if y was non-zero, the branch would execute. We almost never did that on purpose, we usually just forgot to say ==(the equality operator) instead of =(the assignment operator). You can still make this mistake in Javascript.
In C# we have to write it this way...
x = y;
if (x != 0) {
}
It forces us to do the assignment and the test separately. This avoids the problem that often we would mistakenly write the first example, when what we meant was a simple test for equality. There's nothing illegal about doing assignment and testing in the same statement, but the C# compiler warns us that it's probably a mistake - you can force it to compile if you really want.
What I'm saying is C# (and Java) is mostly a reaction to C++ and all of the horrible things it would let you do! So, that's why it's helpful to see an example from old languages periodically and an explanation of why we don't do it that way any more, or why we do. In C#, arrays are managed objects, which is a step up from blocks of memory, but that managed object is just insulating you from all the mistakes that were easy to make when you were closer to the block of memory, which is still there, buried beneath objects. I would expect Petzold to cover that - how C++ was dangerous with memory, how we learned all the pitfalls, and built in safeguards right in the language.
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the book I'm reading now sprinkles in comparisons to C++ every now and then… I got in maybe 20 pages into that other book before I realized they both started off pretty similar… That's when I stopped reading it.
There were a few things mentioned in Petzold's e-book that wasn't covered in the book I'm reading now, which is why am going to eventually read that book when I'm done with my current book.
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how to use counting function in c# for counting values
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There is no specialized counter-function. One declares a variable, and increases it's value when required.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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Do you mean the IList<T>.Count()[^] method? If so, instantiate a list of values, add some values to it, and call Count on it.
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If you are going to get help here, you must first learn how to get help for yourself. Look at the questions you have just posted.
Would you be able to answer them if you knew the answer. No is the short reply.
You need to specify what you need. In this case what are you counting, or why do you need to count something. There is no "counting function" in c#.
The other thing is, you need to explain what the problem is. You will get more help if you show effort on your side. Without this (especially with newer members) everyone assumes you just want your work done for you and won't help - we aren't getting paid.
“Education is not the piling on of learning, information, data, facts, skills, or abilities - that's training or instruction - but is rather making visible what is hidden as a seed”
“One of the greatest problems of our time is that many are schooled but few are educated”
Sir Thomas More (1478 – 1535)
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I strongly suggest you work through .NET Book Zero[^], by Charlse Petzold. It will answer most of the questions you have already posted, and more that you haven't.
Use the best guess
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You could implement a counting function in many ways -
1) Run a loop (for-else, while etc)
2) Call a function recursively
3) Use LINQ
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how to print
*******
*****
***
throug nested loof
in c#
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By writing some code. This is a very simple classroom assignment that you should be able to do for yourself. Think about the steps you need to take:
- How many stars do you need to print on each line?
- How can you use a for loop to change that number by a fixed amount?
- What criteria do you need to test in order to decide when the loop is complete?
If necessary, write all the details on paper before you try turning them into code.
Use the best guess
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