why my code is giving undeclared variable error?

Question

   include "stdafx.h"
#include <vector>
#include <iostream>



    std::vector<int> biggest;

std::vector<int>vector1;
std::vector<int>vector2;


int main(){
biggest = [vector2[0],0]; //wrong initialization
for (int apply = 0; apply < (vector2.size()); apply++) {
    if (biggest[0] < vector2[apply + 1]) {
        biggest[0] = vector2[apply + 1];
        biggest[1] = apply + 1;
    }

}

Error C2065 'apply': undeclared identifier.why this error is occurring as i have already defined apply variable in for loop. error should be in initialization of biggest(vector).why wrong compiler code? even intellisense is not giving me error is it a visual studio bug?

@karanshaarma post a [mcve] as the code above does not reproduce the error. — Richard Critten, Jun 13 '18 at 11:31
@interjay You are right, here is no difference. Might still be a [good idea to get into the habit](https://stackoverflow.com/questions/4706199/post-increment-and-pre-increment-within-a-for-loop-produce-same-output). — KorbenDose, Jun 13 '18 at 11:32
For the same reason we are complaining. Cause both we and the compiler see a name(s) without a matching declaration(s). So we haven't a clue. — StoryTeller - Unslander Monica, Jun 13 '18 at 11:33
yeah i know but these line don't compile.i don't know why? .i am using visual studio 17 community edition. is it's IDE fault? — karan shaarma, Jun 13 '18 at 11:34
sorry guys, i have found the solution i was initializing biggest array in wrong way but don't know why i was getting this kind of error. — karan shaarma, Jun 13 '18 at 11:46
At this point you should either delete the question or show a minimal example to reproduce whatever problem you had that was causing this error. Not showing a minimal example is the reason why you have downvotes on this question. — drescherjm, Jun 13 '18 at 12:52

score 1 · Answer 1 · answered Jun 13 '18 at 11:32

1

apply is in scope in the for loop body, so be assured, the error is not there. But you are aware that apply is out of scope after the loop body?

I'm only answering this because your use of

vector2.size() - 1

will give you hell if vector2 is empty, as the above will wrap around to a large unsigned value and your program will fail spectacularly! Use

for (int apply=0; apply + 1 < vector2.size(); apply++) {

instead.

answered Jun 13 '18 at 11:32

Bathsheba

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i have changed it but still error. let me see if i can upload a snapshot of it – karan shaarma Jun 13 '18 at 11:36
3

@karanshaarma: no, don't upload a snapshot, upload a cut down version of the code that exhibits the error. – Bathsheba Jun 13 '18 at 11:36
sorry guys, i have found the solution i was initializing biggest array in wrong way but don't know why i was getting this kind of error. – karan shaarma Jun 13 '18 at 11:46

why my code is giving undeclared variable error?

1 Answers1