My assignment in Visual Basic 2010 is to build a order form that has two text boxes, one for the name and the other for the address.
And we're suppose to use the IndexOf method on the address.
I understand that IndexOf returns the position of a character and the number of characters.
What would be the purpose of using the IndexOf method on the address in this instance?
I don't understand what I would be searching for when the user types in it's address that's going to be numbers and string characters.
I think I understand what the IndexOf method does, somewhat, but why and what would I use it to achieve?
You'd typically use IndexOf to -
See if a string contained something
If someString.IndexOf("Avenue") > - 1 Then
'do something
End If
Get the start position of a value in a string , this could then be used to extract part of the string. e.g. someString.Substring(someString.IndexOf("#"),10) would get then next ten characters starting from where the "#" character was found in your string.
Bear in mind you'll always need to handle scenarios where IndexOf will return -1 if it does not find the string your searching for, so your code will have to handle that eventuality.
Since this is a homework question, I will answer with a question or several:
How would you normally enter a full address into a text box?
How would each part of the address be distinguishable from another?
Once you figure out how this can be done, think about IndexOf again.
Related
I am using VBA in Ms Access environment, to handle long string (memo field storing HTML originally).
After positioning by Instr(), I put the position into Mid(vStr,vStartPos,vEndPos-vStartPos+1) to extract the string, but the output doesn't match. I have already carefully checked this in immediate windows, as well as NotePad++. What I can say is Instr() and NotePad++ have given the same counting result, while Mid() is different. Mid()'s result are former than Instr()'s in some cases, and latter in other cases. I don't know the reason, and can just believe Mid() use different mechanism or have defeative (surprised!) in handling long string mixed with single-byte and bi-byte chars (but this is common in the world, and meet no problem before), and possibly some special characters.
I believe I need to custom-make a Mid() function. Any idea how to do it effectively and efficiently?
Thanks all for your reply. After I created a custom Mid() by RegEx and find that the problem has no change, I have found out the silly mistake I made. The Instr() and Mid() have no problem, but the string has been carelessly modified between them. So this case should be closed now.
I've implemented auto completion to a combobox like this article shows. Is it possible to make it search for substrings instead of just the beginning of the words?
http://www.codeproject.com/Articles/2371/IAutoComplete-and-custom-IEnumString-implementatio
I haven't found any way to customize how IEnumString/IAutoComplete compares the strings. Is it possible?
The built in search options help a bit but it is complete chaos. To find instring matches you need to set flag AcoWordFilter. But this will prevent from numbers being matched!! However, there is a trick to get the numbers to match: preced with a double-quote as in "3 to find a string containing or starting with "3". Some more chaos? In the AcoWordFilter you also need to prefix other characters not considered part of a "word", eg. you need to prefix parentheses with a " but then you will not find parentheses at the first position!
So the solution is either to create your own implementation of IAutoComplete or offer the user to switch between the modes (a bit awkward).
I dont think that the MS engineers are especially proud of such chaos. How about one more option: AcoSearchAnwhere?
After retrieving the Edit control's IAutoComplete interface, query it for an IAutoComplete2 interface. Calling its SetOptions member you can disable prefix filtering by specifying the ACO_NOPREFIXFILTERING AUTOCOMPLETEOPTIONS.
This is available on Windows Vista and later. If you need a solution that works with pre-Vista versions, you'll have to write your own.
This seems like quite a silly basic question but it seems something I have completely passed over in my knowledge.
Basically I have a string representing a phone number (0 being the area code): 0828889988
And would like to replace the first zero with a 27 (South African dialing code) as I am pretty sure it will always be so, my SMS api requires it in international format but I want the user to enter it in local format, so should be: 27828889988
Is there a line or two of code I can call to replace that first character with the two others?
As is - I can think around a workaround solution but as I am not sure of the direct syntax will be quite a few lines long.
Dim number as String = "0828889988"
number = "27" + number.SubString(1)
return number //returns "27828889988"
I'm working on a translator that will take English language text (as user input into a UITextView) and (with a button press) replace specific words with alternatives. I have both the English words in scope plus their alternatives in separate Arrays (englishArray and alternativeArray), indexed correspondingly.
My challenge is finding an algorithm that will allow me to identify a word in the input text (a UITextView) ignoring characters like <",.()>, lookup the word in englishArray (case insensitive), locate the corresponding word in alternativeArray and then use that word in place of the original - writing it back to the UITextView.
Any help greatly appreciated.
NB. I have created a Category extending the NSArray functionality with a indexOfCaseInsensitiveString method that ignores case when doing an indexOfObject type lookup if that helps.
Tony.
I think that using an NSScanner would be best to parse the string into separate words which you could then pass to your indexOfCaseInsensitiveString method. scanCharactersFromSet:intoString: using a set of all the characters you want to ignore, including whitespace and newline characters should get you to the start of a word, and then you could use scanUpToCharactersFromSet:intoString: using the same set to scan to the end of the word. Using scanLocation at the beginning and end of each scan should allow you to get the range of that word, so if you find a match in your array, you will know where in your string to make the replacement.
Thanks for your suggestion. It's working with one exception.
I want to capture all punctuation so I can recreate the original input but with the substituted words. Even though I have a 'space' in my Character Set, the scanner is not putting the spaces into the 'intoString'. Other characters I specify in the Character Set such as '(' and ';' are represented in the 'intoString'.
Net is that when I recreate the input, it's perfect except that I get individual words running into each other.
UPDATE: I fixed that issue by including:
[theScanner setCharactersToBeSkipped:nil];
Thanks again.
I have url, for example:
http://i.myhost.com/myimage.jpg
I want to change this url to
http://i.myhost.com/myimageD.jpg.
(Add D after image name and before point)
i.e I want add some words after image name and before point using regex.
What is the best way do it using regex?
Try using ^(.*)\.([a-zA-Z]{3,5}) and replacing with \1D\2. I'm assuming the extension is 3-5 alphanumeric numbers but you can modify it to suit. E.g. if it's just jpg images then you can put that instead of the [a-zA-Z]{3,5}.
Sounds like a homework question given the solution must use a regex, on that assumption here is an outline to get you going.
If all you have is a URL then #mathematical.coffee's solution will suit. However if you have a chunk of text within which is one or more URLs and you have to locate and change just those then you'll need something a little more involved.
Look at the structure of a URL: {protocol}{address}{item}; where
{protocol} is "http://", "ftp://" etc.;
{address} is a name, e.g. "www.google.com", or a number, e.g. "74.125.237.116" - there will always be at least one dot in the address; and
{item} is "/name" where name is quite flexible - there will be zero or more items, you can think of them as directories and a file but this isn't strictly true. Also the sequence of items can end in a "/" (including when there are zero of them).
To make a regex which matches a URL start by matching each part. In the case of the items you'll want to match the last in the sequence separately - you'll have zero or more "directories" and one "file", the latter must be of the form "name.extension".
Once you have regexes for each part you just concatenate them to produce a regex for the whole. To form the replacement pattern you can surround parts of your regex with parentheses and refer to those parts using \number in the replacement string - see #mathematical.coffee's solution for an example.
The best way to learn regexs is to use an editor which supports them and just experiment. The exact syntax may not be the same as NSRegularExpression but they are mostly pretty similar for the basic stuff and you can translate from one to another easily.