concatenation

问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: C preprocessor and concatenation Is it possible to concatenate a C preprocessor with a variable name? #define WIDTH 32 int dataWIDTH; // dataWIDTH should be interpreted as 'data32' printf("%d",dataWIDTH); 回答1: Your use case requires a double-unescaping; using the token pasting (##) operator by itself will just append the name of the preprocessor directive. #define WIDTH 32 #define _MAKEDATA(n) data##n #define

问题 In the following two examples I do the same thing, creating a constant String and using the concat method to modify it. Because it's a constant, I expect a compiler warning but only receive one in the second example when I use the assignment operator. Why is this? X = "hello" X.concat(" world") puts X # no warning X = "hello" X = X.concat(" world") puts X # warning: already initialized Since the concat method modifies the string in place, that's normally what I would do, since there's no need

问题 I want to concatenate two arrays of the same type into a single new array with the same type. But the problem is I have to use void pointers, and somehow my code won't work from the third element on. I searched a bit on the internet but seems like noone is having this problem #include <stdio.h> #include <stdlib.h> #include <string.h> void array_float_fill(float *arr1, float *arr2, int n, int m){ for(int i = 0;i<n;i++){ *(arr1+i)=i+n; } for(int i = 0;i<m;i++){ *(arr2+i)=i+m; } } void array

问题 I have 3 strings: a<-c("a1","a2","a3") b<-c("b1","b2","b3") c<-c("c1","c2","c3") How can I get the following output: "a1","b1","c1","a2","b2","c2","a3","b3","c3" Here is what I tried: paste(a,b,c,sep='","') And what I got: [1] "a1\",\"b1\",\"c1" "a2\",\"b2\",\"c2" "a3\",\"b3\",\"c3" Is there a way to do it? Thank you. 回答1: You could also use c(rbind(a,b,c)) which ( rbind ) puts the three variables together into a matrix (row-wise), and then ( c() ) converts them back into a vector, taking

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 7 years ago . Suppose that you have two huge files (several GB) that you want to concatenate together, but that you have very little spare disk space (let's say a couple hundred MB). That is, given file1 and file2 , you want to end up with a single file which is the result of concatenating file1 and file2 together byte-for

问题 I have this line of code which I want to concatenate -or at least solve the loop problem... test = 1 - ("0." & thisnumber(0) & thisnumber(1) & thisnumber(2)) I want this to have a loop in it... -Increasing thisnumber() Until it gets to about 500, Can some implement a loop into this? Or suggest a way... Thanks a lot.. James :) EDIT: So if I had values thisnumber(0) = 1, thisnumber(1) = 5, thisnumber(2) = 0, thisnumber(3) = 7... It would do 1 - 0.1507... (But I want a loop so it does all 500

问题 I have a table with data like this: ID, END_DATE, CLOSE_DATE 1, 2018-05-18, 2018-05-15 2, 2018-05-18, 2018-05-14 3, 2018-05-18, 2018-05-11 4, 2018-05-18, 2018-05-10 I need the output when i query in Oracle server END_DATE CLOSE_DATE ID 2018-05-18 [2018-05-15,2018-05-14,2018-05-11,2018-05-10] [1,2,3,4] I have tried to use listagg, but its working either for Id or Close Date but not both. select (listagg(CLOSE_DATE,',') within group (order by CLOSE_DATE DESC)) CLOSE_DATE , END_DATE from TBL_S

问题 I am trying to write a div element from javascript. I want the line written as follows, using document.write(): <div class="Square15px" onmouseover="changeColor('boxid')"></div> I call the function that writes the div element with: <script type="text/javascript"> colorPicker("box1"); </script> I have tried the document.write() method, building the string several different ways such as: function colorPicker(box) { var box = document.getElementById(box); var boxid = box.id; var AquaStr1 = '<div

问题 The question is simple: what's frong with this piece of code? size_t buff = 1; size_t new_buff; WCHAR *var_path; WCHAR *dir_path; var_path = new WCHAR[buff]; new_buff = GetEnvironmentVariableW(L"APPDATA", var_path, buff); if (new_buff == 0) { return 1; } else if (new_buff > buff) { delete[] var_path; var_path = new WCHAR[new_buff]; GetEnvironmentVariableW(L"APPDATA", var_path, new_buff); } dir_path = new WCHAR[new_buff]; wcscpy_s(dir_path, new_buff, var_path); wcscat_s(dir_path, new_buff, L"\

问题 I try to work with a concatenated text in the setter of a textblock. textblock looks like that: <TextBlock> <Run Text="{x:Static languages:visuTexts.Lenght}" /> <Run Text="A [LA]"/> <TextBlock.Style> <Style TargetType="TextBlock" BasedOn="{StaticResource {x:Type TextBlock}}"> <Style.Triggers> <DataTrigger Binding="{Binding Product.DiameterA}" Value="0"> <Setter Property="Text" Value="concatenated text here" /> </DataTrigger> </Style.Triggers> </Style> </TextBlock.Style> </TextBlock> i want to