I'm working on C++,
i have one string as follows:
string str = "rake::may.chipola::ninbn::myFuntion";
How to get last element from above string which is always after the last occurrence of "::"?
Use std::string::rfind() to locate the last occurrence of :: and use std::string::substr() to extract the token:
// Example without confirming that a '::' exists.
std::string last_element(str.substr(str.rfind("::") + 2));
Related
I have a string like this
str = ["asap subject ssfs sfdsf sdfsdfsdefs sdfssdf","nsubject qwerty
swqt","dsfsdf sdfsdf sdfsfs sfsdf er:subject adsdsd dsdfs
sdfsdfsdfsds"]
What i Want
str = ["ssfs sfdsf sdfsdfsdefs sdfssdf","qwerty
swqt","adsdsd dsdfs sdfsdfsdfsds"]
I using
for i in range(0,len(str)):
list_i.append(str[i].strip("subject*)[1])
But problem is when i have long text after subject and i want value of current line only.
Seems like you should be using the str.split function.
Instead of
str[i].strip("subject")[1]
replace that with
str[i].split("subject ",1)[-1]
This splits the string at "subject", then takes the last element of that result.
If I want search first occurrence of letter in str1. If my str include both letter and number and symbol, but First I just want search location of letter like"a","b","c","d"...
can I create a string arr
string str[]={"a","b","c","d","e"....};
str1="signal a: a<= '0';";
str1.find(str,0);
can I do like this?
And I want to ask another question about string size
string str="signal a";
cout<<str.size()<<endl;
size of this string should be 8, but it actually just gives me 86?
I try to locate a special part in a string.
The example of string as follow:
22.21594087,1.688530832,0
I want to locate 1.688530832 out.
I tried
temp.substr(temp.find(",")+1,temp.rfind(","));
and got 1.688530832,0.
I replaced rfind() with find_last_of() but still got the same result.
temp.substr(temp.find(",")+1,temp.find_last_of(","));
I know this is a simple problem and there are other solutions.But I just want to know why the rfind did not work.
Thank you very much!
The second argument for substr is not the ending index, but rather the length of the substring you want. Simply throw in the length of 1.688530832 and you'll be fine.
If the length of the search string is not available, then you can find the position of the last comma and subtract that from the position of the first character of the special word:
auto beginning_index = temp.find(",") + 1;
auto last_comma_index = temp.rfind(",");
temp.substr(beginning_index, last_comma_index - beginning_index);
I see what you are doing. You are trying to have kind of iterators to the beginning and the end of a substring. Unfortunately, substr does not work that way, and instead expects an index and an offset from that index to select the substring.
What you were trying to achieve can be done with std::find, which does work with iterators:
auto a = std::next(std::find(begin(temp), end(temp), ','));
auto b = std::next(std::find(rbegin(temp), rend(temp), ',')).base();
std::cout << std::string(a, b);
Live demo
I have the following string:
{'output',{'variable','VGRG_Pos_Var1/Parameters/D_foo'},'date',734704.60904050921}
I would like to verify the format of the string that the word 'variable' is the second word and i would like to retrive the string after the last '/' in the 3rd string (In this example 'D_foo').
how could i verify this and retrive the sting i search?
I tried the following:
regexp(str,'{''\w+'',{''variable'',''([(a-z)|(A-Z)|/|_])+')
without success
REMARK
The string to analysis is not splited after the komma, it is only due to length of the string.
EDIT
my string is:
'{''output'',{''variable'',''VGRG_Pos_Var1/Parameters/D_foo''},''date'',734704.60904050921}';
and not a cell, which could be understood. I added the sybol ' at the start and end of the string to symbolizied that it is a string.
I realise that you mention using regexp in the question, but I'm not sure if this is a requirement? If other solutions are acceptable you could try this:
str='{''output'',{''variable'',''VGRG_Pos_Var1/Parameters/D_foo''},''date'',734704.60904050921}';
parts1=textscan( str, '%s','delimiter',{',','{','}'},'MultipleDelimsAsOne',1);
parts2=textscan( parts1{1}{3}, '%s','delimiter',{'/',''''},'MultipleDelimsAsOne',1);
string=parts2{1}{end}
match=strcmp(parts1{1}{2},'variable')
To answer the first part of your question, you can write this:
str = {'output',{'variable','VGRG_Pos_Var1/Parameters/D_foo'},'date',734704.60904050921};
temp = str(2); %this holds the cell containing the two strings
if cmpstr(temp{1}(1), 'variable')
%do stuff
end
For the second part you can do this:
str = {'output',{'variable','VGRG_Pos_Var1/Parameters/D_foo'},'date',734704.60904050921};
temp = str(2); %like before, this contains the cell
temp = temp{1}(2); %this picks out the second string in the cell
temp = char(temp); %turns the item from a cell to a string
res = strsplit(temp, '/'); %splits the string where '/' are found, res is an array of strings
string = res(3); %assuming there will always be just 2 '/'s.
I did a program to remove a group of Characters From a String. I have given below that coding here.
void removeCharFromString(string &str,const string &rStr)
{
std::size_t found = str.find_first_of(rStr);
while (found!=std::string::npos)
{
str[found]=' ';
found=str.find_first_of(rStr,found+1);
}
str=trim(str);
}
std::string str ("scott<=tiger");
removeCharFromString(str,"<=");
as for as my program, I got my output Correctly. Ok. Fine. If I give a value for str as "scott=tiger" , Then the searchable characters "<=" not found in the variable str. But my program also removes '=' character from the value 'scott=tiger'. But I don't want to remove the characters individually. I want to remove the characters , if i only found the group of characters '<=' found. How can i do this ?
The method find_first_of looks for any character in the input, in your case, any of '<' or '='. In your case, you want to use find.
std::size_t found = str.find(rStr);
This answer works on the assumption that you only want to find the set of characters in the exact sequence e.g. If you want to remove <= but not remove =<:
find_first_of will locate any of the characters in the given string, where you want to find the whole string.
You need something to the effect of:
std::size_t found = str.find(rStr);
while (found!=std::string::npos)
{
str.replace(found, rStr.length(), " ");
found=str.find(rStr,found+1);
}
The problem with str[found]=' '; is that it'll simply replace the first character of the string you are searching for, so if you used that, your result would be
scott =tiger
whereas with the changes I've given you, you'll get
scott tiger