Develop Reference

How can I have x many symbols on the first line then adding 1 more each line until it hits the end value with a for loop?

So I want to recreate this process with a for loop. What's the simplest way of doing this. I can do 1 to 10 but let's say you have 3 as your start value I can't get the first line to start with 3 symbols.
Thanks in advance.

Since you haven't shared any code, I'll give you an idea as to how you can print the values. I've used 2 for loops to print the value. Although there maybe better and shorter algorithms to do the same
Just edit my code below to suit your needs.
public static void Main()
{
var start = 3; //StartTextBox.Text
var end = 10; //EndTextBox.Text
var symbol = "#"; //SymbolTextBox.Text
for (var i = start; i < end; i++)
{
var toPrint = string.Empty;
for (var j = 0; j < i; j++) toPrint += symbol;
Console.WriteLine(toPrint); //LabelX.Text = toPrint;
}
Console.ReadLine();
}
You can see in the above code that if you change the value of start to any number, the value gets printed properly.

Another option assuming some of your object names...
for (int i = int.Parse(txtStart.Text); i <= int.Parse(txtEnd.Text); i++)
{
lblOutput.Text += new String(txtSymbol.Text.ToCharArray()[0], i) + Environment.NewLine;
}

Exiting loop without break/return/if

If you have a for loop:
for(i=0;i<10;i++){}
Now, when i==5, how can I exit the for loop completely without using break, return, or if?

The best I could come up with was this:
for (int i = 0; i < 10; i++)
{
i = (i == 5) ? 10 : i;
Trace.WriteLine("i = " + i.ToString());
}
...which will cause the loop to run six times (i=0..5) and display this..
i = 0
i = 1
i = 2
i = 3
i = 4
i = 10
The alternative way to "exit the loop" (in a particularly nasty fashion) would be to do this...
for (int i = 0; i < 10; i++)
{
int a = 3 / ((i == 5) ? 0 : 1);
Trace.WriteLine("i = " + i.ToString());
}
..which crashes out, errr, successfully exits the loop without using the break, return or if commands.
i = 0
i = 1
i = 2
i = 3
i = 4
A first chance exception of type 'System.DivideByZeroException' occurred in MikesProgram.dll
language is C# .it was an interview question actually..curious
Do I get the job ?
I would need to check your health & dental plans, and I have to leave early on Thursdays to collect my daughters from school.
;-)

for (int n = 0; n < 10; n++)
{
n += (n / 5) * 5;
}

well here's another way if you want to break the processing exactly when i = 5 without using break, return, or if
for (int lowsetLimit = 0, highestLimit = 10, i = lowsetLimit; i < highestLimit; i++)
{
//normal code which process before i gets eqaul to 5 goes here...
i = (i < 5) ? i : highestLimit; //and here is the pivot point.
}

for(i=0;i<10;i++){
(i==5) ? goto Outer : //do something;
}
Outer:
//do something

The question says that loop should end when i=5, It says nothing about start, So this should be valid (ternary operator solution is better, but if we are not allowed to use any conditional operator)
for (int i = 0; i < 10; i++)
{
i=i-4;
Console.WriteLine("i = " + i.ToString());
i=i+4;
}
this Starts at -4 and ends at 5.

The real answer of course would be the following:
for (i=0; i!=5; i++)
{
// do something
}
But let's make it a bit more generic: stop if (expression) becomes true.
The second argument of the for loop is a boolean expression which determines whether to continue the loop with the next element or not.
So if you want to stop looping because of any condition:
for (i=0; !(expression) && i<10; i++)
{
// do something
}

This works using while and goto:
for (int i = 0; i < 10; i++)
{
while (i < 5)
{
Console.Write(i + " ");
goto OutsideWhile;
}
OutsideWhile:
continue;
}
// 0 1 2 3 4

Get number inside of a string and do a loop

I want to get a number of a string, and separate the string and the number, and then, do a loop and call a method the number of times the string says.
The string has to have this structure: "ABJ3" (Only one number accepted and 3 characters before it)
This is my code, but it repeat hundred of times, I don't know why
int veces = 0;
for (int i = 0; i < m.Length; i++)
{
if (Char.IsDigit(m[i]))
veces = Convert.ToInt32(m[i]);
}
if (m.Length == 4)
{
for (int i = 0; i <= veces; i++)
{
m = m.Substring(0, 3);
operaciones(m, u, t);
Thread.Sleep(100);
}
}
operaciones(m,u,t);
if (u.Length >= 14)
{
u = u.Substring(0, 15);
}
Some help please?

You have to convert your m[i] ToString() right now you are sending the char value to Convert.ToInt32 and that is a much higher value (9 = 57 for example)
char t = '9';
int te = Convert.ToInt32(t.ToString());
Console.WriteLine(te);
This gives us a result of 9 but
char t = '9';
int te = Convert.ToInt32(t);
Console.WriteLine(te);
Gives us a result of 57
So you need to change
veces = Convert.ToInt32(m[i]);
to
veces = Convert.ToInt32(m[i].ToString());
Hope it helped.
Best regards //KH.

You cannot convert the digits like this. You're overwriting them and taking only the last one. Moreover, you're taking its ASCII code, not digit value. You have to extract all digits first then convert them:
int position = 0;
int veces = 0;
string temp = ""
for (int i = 0; i < m.Length; i++) {
if (Char.IsDigit(m[i]))
position = i;
else
break;
}
veces = Convert.ToInt32(m.SubString(0, i + 1));
Alternatively, you can use regex instead.

How To Add Two List<> at run time ? Index out of range error My code Attached (ASP.net C#)

I am trying to add two lists in a loop by adding first index value of one list to the first index value of another list but both list are populating at run time after calculation issue is that how to track that list<> posses value at that index or not as shown below ,
Result[var]=first[var]+second[var]
complete code is give below,
List<double> Result = new List<double>();
for (int var = 0; var < 30; var++)
{
if (first[var] == null)
{
first[var] = 0;
}
if (second[var] == null)
{
second[var] = 0;
}
}
Result[var]=first[var]+second[var];
}
we do are not sure that both list may have value up to 10,15 .. index but i need if list one have 15 values and list two have 10 values then add two list in this way ,
A list[0]+B list[0]=
A list[1]+B list[1]=
A list[2]+B list[2]=
if it add
A list[11]+B list[11]=
then it add 0 from second list because it has only 10 values then how to validate b list[11] and use 0 if index 11 not exist in second list
one more thing list can have upto 30 values maximum not more then 30

You may need something like this (assuming that first and second are List):
List<double> Result = new List<double>();
for (int i = 0; i < 30; i++)
{
double firstVal = 0;
double secondVal = 0;
if (first.Count > i)
{
firstVal = first[i];
}
if (second.Count > i)
{
secondVal = second[i];
}
Result.Add(firstVal + secondVal);
}

If I understood correctly, you are trying to add two list values into another list. If one of the list is ended, consider the value as zero and continue till max available limit of either of the lists.
If so,
// assume i1, i2 are sources and i3 is result
int max = i1.Count>i2.Count?i1.Count:i2.Count;
for (int i = 0; i < max; i++)
{
i3[i] = (i1.Count > i ? i1[i] : 0) + (i2.Count > i ? i2[i] : 0);
}
// another varient:
for (int i = 0; i < i1.Count; i++)
{
i3[i] = i1[i] + (i2.Count > i ? i2[i] : 0);
}
for (int i = i1.Count; i < i2.Count; i++)
{
i3[i] = i2[i];
}

C# looping through an array

I am looping through an array of strings, such as (1/12/1992 apple truck 12/10/10 orange bicycle). The array's length will always be divisible by 3. I need to loop through the array and grab the first 3 items (I'm going to insert them into a DB) and then grab the next 3 and so on and so forth until all of them have been gone through.
//iterate the array
for (int i = 0; i < theData.Length; i++)
{
//grab 3 items at a time and do db insert, continue until all items are gone. 'theData' will always be divisible by 3.
}

Just increment i by 3 in each step:
Debug.Assert((theData.Length % 3) == 0); // 'theData' will always be divisible by 3
for (int i = 0; i < theData.Length; i += 3)
{
//grab 3 items at a time and do db insert,
// continue until all items are gone..
string item1 = theData[i+0];
string item2 = theData[i+1];
string item3 = theData[i+2];
// use the items
}
To answer some comments, it is a given that theData.Length is a multiple of 3 so there is no need to check for theData.Length-2 as an upperbound. That would only mask errors in the preconditions.

i++ is the standard use of a loop, but not the only way. Try incrementing by 3 each time:
for (int i = 0; i < theData.Length - 2; i+=3)
{
// use theData[i], theData[i+1], theData[i+2]
}

Not too difficult. Just increment the counter of the for loop by 3 each iteration and then offset the indexer to get the batch of 3 at a time:
for(int i=0; i < theData.Length; i+=3)
{
var item1 = theData[i];
var item2 = theData[i+1];
var item3 = theData[i+2];
}
If the length of the array wasn't garuanteed to be a multiple of three, you would need to check the upper bound with theData.Length - 2 instead.

Your for loop doesn't need to just add one. You can loop by three.
for(int i = 0; i < theData.Length; i+=3)
{
string value1 = theData[i];
string value2 = theData[i+1];
string value3 = theData[i+2];
}
Basically, you are just using indexes to grab the values in your array. One point to note here, I am not checking to see if you go past the end of your array. Make sure you are doing bounds checking!

This should work:
//iterate the array
for (int i = 0; i < theData.Length; i+=3)
{
//grab 3 items at a time and do db insert, continue until all items are gone. 'theData' will always be divisible by 3.
var a = theData[i];
var b = theData[i + 1];
var c = theData[i + 2];
}
I've been downvoted for this answer once. I'm pretty sure it is related to the use of theData.Length for the upperbound. The code as is works fine because array is guaranteed to be a multiple of three as the question states. If this guarantee wasn't in place, you would need to check the upper bound with theData.Length - 2 instead.

Here is a more general solution:
int increment = 3;
for(int i = 0; i < theData.Length; i += increment)
{
for(int j = 0; j < increment; j++)
{
if(i+j < theData.Length) {
//theData[i + j] for the current index
}
}
}

string[] friends = new string[4];
friends[0]= "ali";
friends[1]= "Mike";
friends[2]= "jan";
friends[3]= "hamid";
for (int i = 0; i < friends.Length; i++)
{
Console.WriteLine(friends[i]);
}Console.ReadLine();