I am having issues with c# (new to it) but with some programming experience (not great, many moons ago, Python)
I must be doing something wrong and looking for the answer incorrect, spent a couple of days searching for this. I think its really simple and I must be doing something wrong.
Basically I want to take a user input of an interger and store it as an array so I perform maths on individual numbers. However, when I try and get the console to read the number I can not then access the 4th position etc because as c# keeps telling me.
Cannot apply indexing with [] to an expression of type int
what elemental mistake am I making here guys,
Edited to improve original question.
sorry all, that was a little vague. Let me show you how my idea works in python and maybe that would help matters. Basically, i'm trying to access the positions of an integer.
Number = (input("Please enter a Number number"))
check_digit = number[7]
loyalty = number[:-1]
I want the user to enter the number and then the program access different numbers in the array.
Judging from the exception, you probably declare you Array like this:
int myArray;
Instead of this:
int[] myArray;
Error 1 Cannot apply indexing with [] to an expression of type 'int'
Related
I have recently began to start learning C# and try to write a program that's similar to a calculator in a console. I've already done it with two integers and it worked. Now I am trying to write the code allowing more user inputs to calculate with.
The thing is, that I have stuck at spliting the string from the user-input. So let's say for example he writes:
1 + 2 * 3 - 5 I want to split it where the space happens. It should still be splitting when the user uses more than just one spaces in between. It's like the same as 1,2,,3,,,,5,6,,,4 : How can you split by the comma when there are MORE than one comma used? I only want the integers (and the operators from example 1).
I have already tried with [string_name].Split(' ') and [string_name].Split(',') but it only seems to ignore ONE char variable between the user-input-values I am interested in. That makes it impossible for me to put the values in an array and convert them to int.
Last question regarding my first example (1 + 2 * 3 - 5):
Besides accepting multiple spaces/comma, how can you split this string input efficiently, keeping int inputs and the operators? My idea was to save every uneven input value (1, 2, 3, 5) and every even input value (+, *, -,/) in an array each. I considered to put the operators into a switch with 4 cases and convert the string_array with numbers to integers. After that I would have put them all together into the exact same order like the user-input using for.
The thing is: Assuming I implement it correctly, I think that the calculation would be solved from left to right without considering the precedence of '*' and '/'.
Someone an idea how you can solve this problem with the "advanced" calculator efficiently? I have thought for a long time and tried all I could, but it doesn't seem to work ... Makes me sad a bit. I'd really like to solve this problem somehow.
Well the answer to your first question, you can pass an overload to Split that will ignore empty entries:
str.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
So more traditionally, you'd want to parse the string entirely so you could handle things like parenthesis and the case where there is no space: 4*(1+2) for instance.
I am trying to use the speechrecognitionengine to recognize a grammar that includes some choices from a specific set, followed by an arbitrary numeric value followed by a choice set. So "[Choice1,Choice2,Choice3] 1563 [ChoiceA,ChoiceB,ChoiceC]" Doing this with by appending a Choices array, AppendDictation() and Appending another Choices grammer works well, except that the number recognized in the AppendDictation portion comes through as "One thousand five hundred sixty-three" instead of 1563. This is counter intuitive to me because if you replace all of the above with a DictationGrammer, the number is recognized as 1563 instead of that long form example above. I would prefer to use the GrammarBuilder method with specific choice sets to increase the likelihood the right commands / phrase are recognized. Any help would be appreciated, thanks!
Also, I can't just add numbers into a Choices array because it would need to be massive due to the range of possible numbers.
Try this:
AppendDictation("spelling");
This workaround however, will not work if you say anything above 9, so for 1563 you will have to say out loud "one, five, six, three". The resulting text will be 1563.
Alternatively you could try what has been answered in this post: Converting words to numbers in PHP
Edit: Better answer in this post. Has the function to convert words into actual numbers Convert words (string) to Int
I came across this question in an interview:
We have to find out the number of occurences of two given words in a text file with <=n words between them.
Example1:
text:`this is first string this is second string`
Keywords:`this, string`
n= 4
output= 2
"this is first string" is the first occurrence and number of words between this and string is 2(is, first) which is less than 4.
this is second string is the remaining string. number of words between *this and string * is 2 (is, second) which is less than 4.
Therefore the answer is 2.
I have thought that I will use
Dictionary<string, List<int>>.
My idea was that I use the dictionary and get the list of places where the particular word is repeated and then iterate through both the lists, increment the count if a condition is met and then display the count.
Is my thinking process correct? Please provide any suggestions to improve my solution.
Thanks,
Not an answer per-se (as quite honestly, I don't understand the question :P), but to add some general interview advice to the other answers:
In interviews the interviewer is always looking for the thought process and that you are a critical, logical thinker. Not necessarily that you have excellent coding recall and can compile code in your brain.
In addition interviews are a stressful process. By slowing down and talking out loud as you work things out you not only look like a better communicator and logical thinker (even if getting the question wrong), you also give yourself time to think.
Use a pen and paper, speak as you think, start off from the top and work through it. I've got jobs even if I didn't know the answers to tech questions by demonstrating that I can at least try to work things out ;-)
In short, it's not just down to technical prowess
I think it depends if the call is done only one or multiple times per string. If it's something like
int getOccurences(String str, String reference, int min_size) { ... }
then you don't really need the dictionary, not even a ist. You can just iterate through the string to find occurrences of words and then check the number of separators between them.
If on the other hand the problem is for arbitrary search/indexing, IMHO you do need a dictionary. I'd go for a dictionary where the key is the word and the value is a list of indexes where it occurs.
HTH
If you need to do that repeatedly for different pairs of words in the same text, then a word dictionary with a list of indexes is a good solution. However, if you were only looking for one pair, then two lists of indexes for those two words would be sufficient.
The lists allow you to separate the word detection operation from the counting logic.
How can I retrieve the highest number in an array recursively in C#?
Right now you're probably thinking that we're mean for not giving you the answer -- and I admit that I have the answer written down and part of me wants to give it to you, even.
Programming is all about finding the solutions to problems yourself. When you're hired as a programmer, you may have other people to lean on, but they've all got their own problems, and you'll need to be able to pull your own weight.
Recursion (in an oversimplifed answer) means to call the same operation over and over until the result is produced. That means you need in every recursive operation, you need to know (at least) two things:
What you're looking for
What you've found so far
The 'What you're looking for' is the termination condition. Once you find that, all work can stop and you can go home.
The 'what you've found so far' is how you know what've you've checked so you don't retread old ground.
So what do you need to know in order to find the highest value in an array recursively?
The contents of the Array.
The highest number you've found so far.
Have you already looked at this part of the Array? (Why look through it again?)
That would produce a method signature that looks like:
public int GetHighestNumber(int[] array, int highestNumberFound, int lastIndexChecked);
Once you're inside the array, you've got to do the following:
Iterate through the array
Stop when you find a value that is higher than the highestNumberFound
Call GetHighestNumber again with the new highestNumberFound and lastIndexChecked updated.
When there are no more 'higher' numbers, then return the highest number found.
I realize it sounds trite, but learning this stuff on your own will make you a better programmer.
If you want to be a professional programmer, you have got to learn this stuff on your own.
If you don't want to be a professional programmer, then drop the course and do something you love.
Here's just a hint (taking int[] as an example):
public int FindMax(int[] array, int indexSoFar, int maxSoFar)
Think about:
The start conditions
The termination conditions
How you move through the array recursively
Reason of EDIT: Didnt want to spoil the answere.
Greetings.
This is just a quick question in C#.
I have a scenario where I am working with several devices that all have slightly different data to work with.
When I work out which device I am using, I want to set up a common array to use throughout the code, say arrayCommon.
So I want to move the info from device1 to the common array.
Do I have to do this in a loop for each occurance in the array or can u move the whole array into the common array, as you could in Cobol all those years ago ?
Thanks, George.
I think you are looking for that : Array.Copy
Just a note, if you are needing it in a performance critical section of code, rather use:
Buffer.BlockCopy()
Link here.
Array array = new char["String".Length];
"String".ToCharArray().CopyTo(array, 0);