I am new in C and I am trying to copy an upper part of a string like for example the string is "Let's go to the mall". I would like to place only "Let's go to the" to a newly allocated pointer then later on concatenate it with something else. Can someone suggest how I could implement this?
I am thinking of something like this:
char *sample = "Let's go to the mall";
char *lower_half = " club and dance";
char *upper_half = malloc(sizeof(sample) + sizeof(lower_half));
strcpy(upper_half,sample); <<<<------- How can i copy the "Let's go to the"?
strcat(upper_half,lower_half);
printf("String:%s\n",upper_half);
Then the result would be "Let's go to the club and dance".
I am also not sure if my allocation for upper_half is right. Is it too large?
Try :
strncpy(upper_half,sample,15); // with last parameter, number of char to copy.
strcat(upper_half,lower_half);
Related
So I am going off memory here because I cannot see the code I am trying to figure this out for at the moment, but I am working with some old VB Script code where there is a data connection that is set like this:
set objCommand = Server.CreateObject("ADODB.command")
and I have a field from the database that is being stored in a variable like this:
Items = RsData(“Item”).
This specific field in the database is a long string of
text:
(i.e. “This is part of a string of text…Header One: Here is text after header one… Header Two: Here is more text after header two”).
There are certain parts of the text that I wish to store as a variable that are between two index positions in the long string of text within that field. They are separated by headers that are stored in the text field above like this: “Header One:” and “Header Two:”, and I want to capture all text that occurs in between those two headers of text and store them into their own variable (i.e. “Here is text after header one…”).
How do I achieve this? I have tried to use the InStr method to set the index but from how I understand how this works it will only count the beginning of where a specific part of the string occurs. Am I wrong in my thinking of this? Since that is the case, I am also having trouble getting the Mid function to work. Can some one please show me an example of how this is supposed to work? Remember, I am only going off of memory so please forgive me that I am unable to provide better code examples now. I hope my question makes sense!
I am hopeful that someone can help me with an answer tonight so I can try this out tomorrow when I am near the code again! Thank you for your efforts and any help offered!
You can extract all the substrings starting with the text Header and ending just before either the next Header or end-of-string. I have used regular expression to implement that and it is working for me. Have a look at the code below. If I get a simpler(non-regex solution), I will update the answer.
Code:
strTest = "Header One: Some random text Header Two: Some more text Header One: Some random textwerwerwefvxcf234234 Header Three: Some more t2345fsdfext Header Four: Some randsdfsdf3w42343om text Header Five: Some more text 123213"
set objReg = new Regexp
objReg.Global = true
objReg.IgnoreCase = false
objReg.pattern = "Header[^:]+:([\s\S]*?)(?=Header|$)" '<---Regex Pattern. Explained later.
set objMatches = objReg.Execute(strTest)
Dim arrHeaderValues() '<-----This array contains all the required values
i=-1
for each objMatch in objMatches
i = i+1
Redim Preserve arrHeaderValues(i)
arrHeaderValues(i) = objMatch.subMatches.item(0) '<---item(0) indicates the 1st group of each match
next
'Displaying the array values
for i=0 to ubound(arrHeaderValues)
msgbox arrHeaderValues(i)
next
set objReg = Nothing
Regex Explanation:
Header - matches Header literally
[^:]+: - matches 1+ occurrences of any character that is not a :. This is then followed by matching a :. So far, keeping the above 2 points in mind, we have matched strings like Header One:, Header Two:, Header blabla123: etc. Now, whatever comes after this match is relevant to us. So we will capture that inside a Group as shown in the next breakup.
([\s\S]*?)(?=Header|$) - matches and captures everything(including newlines) until either the next Header or the end-of-the-string(represented by $)
([\s\S]*?) - matches 0+ occurrences of any character and capture the whole match in Group 1
(?=Header|$) - match and capture the above thing until another instance of the string Header or end of the string
Click for Regex Demo
Alternative Solution(non-regex):
strTest = "Header One: Some random text Header Two: Some more text Header One: Some random textwerwerwefvxcf234234 Header Three: Some more t2345fsdfext Header Four: Some randsdfsdf3w42343om text Header Five: Some more text 123213"
arrTemp = split(strTest,"Header") 'Split using the text Header
j=-1
Dim arrHeaderValues()
for i=0 to ubound(arrTemp)
strTemp = arrTemp(i)
intTemp = instr(1,strTemp,":") 'Find the position of : in each array value
if(intTemp>0) then
j = j+1
Redim preserve arrHeaderValues(j)
arrHeaderValues(j) = mid(strTemp,intTemp+1) 'Store the desired value in array
end if
next
'Displaying the array values
for i=0 to ubound(arrHeaderValues)
msgbox arrHeaderValues(i)
next
If you don't want to store the values in an array, you can use Execute statement to create variables with different names during run-time and store the values in them. See this and this for reference.
In my code, i have switch case such as
switch(iSortCol) {
case1: if(iSortDir="desc"){order1 = order1.OrderByDescending(x=>x.GROUPNAME);
elseif(iSortDir="asc")order1 = order1.OrderBy (x=>x.GROUPNAME);
case2: if(iSortDir="desc"){order1 = order1.OrderByDescending(x=>x.GROUPMASTERID);
elseif(iSortDir="asc")order1 = order1.OrderBy (x=>x.GROUPMASTERID);}
....
case80:
case81:
}
The growing of "switch...case..." leads more maintain work for the code, i am thinking how to covert the code to Dictionary or strategy pattern for a better maintainability.
By the way, the property in order 1 such as "GROUPNAME","GROUPMASTERID" has different type
E.g. the "GROUPNAME" in (x=>x.GROUPNAME) is string type, but the "GROUPMASTERID" in (x=>x.GROUPMASTERID) int type.
Could anyone give me some clues, really appreciated
I have a code someone wrote and there
this->llBankCode = new widgetLineEditWithLabel(tr("Bankleitzahl"), "", Qt::AlignTop, this);
QRegExpValidator *validatorBLZ = new QRegExpValidator(this);
validatorBLZ->setRegExp(QRegExp( "[0-9]*", Qt::CaseSensitive));
this->llBankCode->lineEdit->setValidator(validatorBLZ);
as it can be seen from this code, is that validatorBLZ can accept only numbers between 0 and 9. I would like to change it, that validatorBLZ would be able to get as an input whitespace as well (but not to start with a whitespace), but it wont be shown.
Example:
if i try to copy & paste a string of the format '22 34 44', the result would be an empty field. What i would like to happen is that the string '22 34 44' will be shown in the field as '223444'.
How could i do it?
You could try using:
QString string = "22 34 44";
string.replace(QString(" "), QString(""));
That will replace any spaces with a non-space.
Write your own QValidator subclass and reimplement validate and fixup. Fixup does what you ask for: changes the input in a way that makes it intermediate/acceptable.
In your case, consider the following code-snippet for fixup:
fixup (QString &input) const
{
QString fixed;
fixed.reserve(input.size());
for (int i=0; i<input.size(); ++i)
if (input.at(i).isDigit()) fixed.append(input.at(i));
input = fixed;
}
(this is not tested)
The validate function will obviously look similar, returning QValidator::Invalid when it encounters a non-digit character and returning the according position in pos.
If your BLZ is limited to Germany, you could easily add the validation feature that it only returns QValidator::Acceptable when there are eight digits, and QValidator::Intermediate else.
Anyhow, writing an own QValidator, which often is very easy and straight forward, is the best (and most future-proof) solution most of the time. RegExes are great, but C++ clearly is the more powerful language here, which in addition results in a much more readable validator ;).
Right now my flashcard game is using a prepvocab() method where I
define the terms and translations for a week's worth of terms as a dictionary
add a description of that week's terms
lump them into a list of dictionaries, where a user selects their "weeks" to study
Every time I add a new week's worth of terms and translations, I'm stuck adding another element to the list of available dictionaries. I can definitely see this as not being a Good Thing.
class Vocab(object):
def __init__(self):
vocab = {}
self.new_vocab = vocab
self.prepvocab()
def prepvocab(self):
week01 = {"term":"translation"} #and many more...
week01d = "Simple Latvian words"
week02 = {"term":"translation"}
week02d = "Simple Latvian colors"
week03 = {"I need to add this":"to self.selvocab below"}
week03d = "Body parts"
self.selvocab = [week01, week02] #, week03, weekn]
self.descs = [week01d, week02d] #, week03, weekn]
Vocab.selvocab(self)
def selvocab(self):
"""I like this because as long as I maintain self.selvocab,
the for loop cycles through the options just fine"""
for x in range(self.selvocab):
YN = input("Would you like to add week " \
+ repr(x + 1) + " vocab? (y or n) \n" \
"Description: " + self.descs[x] + " ").lower()
if YN in "yes":
self.new_vocab.update(self.selvocab[x])
self.makevocab()
I can definitely see that this is going to be a pain with 20+ yes no questions. I'm reading up on curses at the moment, and was thinking of printing all the descriptions at once, and letting the user pick all that they'd like to study for the round.
How do I keep this part of my code better maintained? Anybody got a radical overhaul that isn't so....procedural?
You should store your term:translation pairs and descriptions in a text file in some manner. Your program should then parse the text file and discover all available lessons. This will allow you to extend the set of lessons available without having to edit any code.
As for your selection of lessons, write a print_lesson_choices function that displays the available lessons and descriptions to the user, and then ask for their input in selecting them. Instead of asking a question of them for every lesson, why not make your prompt something like:
self.selected_weeks = []
def selvocab(self):
self.print_lesson_choices()
selection = input("Select a lesson number or leave blank if done selecting: ")
if selection == "": #Done selecting
self.makevocab()
elif selection in self.available_lessons:
if selection not in self.selected_weeks:
self.selected_weeks.append(selection)
print "Added lesson %s"%selection
self.selvocab() #Display the list of options so the user can select again
else:
print "Bad selection, try again."
self.selvocab()
Pickling objects into a database means it'll take some effort to create an interface to modify the weekly lessons from the front end, but is well worth the time.
Afternoon all.
A very simple one for you today from thicky Rich.
I have a label I want to display as a lovely number format i.e. {0:N0}
Now, this label text equates to a query string value.
How do I go about formatting a label's text from a query string value in one fell swoop?
I have tried this
lblTotalPurchQS.Text = String.Format("{0:N0}",Request.QueryString["totalpurchasequantity"].ToString());
but with little success.
Any ideas or pointers?
Don't use ToString on the incoming query string parameter, but convert it to an int first:
lblTotalPurchQS.Text = String.Format("{0:N0}", int.Parse(Request.QueryString["totalpurchasequantity"]));
Note:
The above is not safe code. First, the conversion may fail with a conversion exception. You should also be HTML escaping the output, in case of XSS.
This is better:
int totalPurchaseQuantity;
if(int.TryParse(Request.QueryString["totalpurchasequantity"], out totalPurchaseQuantity))
{
lblTotalPurchQS.Text = Server.HtmlEncode(String.Format("{0:N0}", totalPurchaseQuantity);
}