How to adjust bugs in general projects ----- take you through the whole process by hand

The example only tells you how to find bug, Will not be too specific bug The solution of the . because bug Too much , There are many solutions . The most important thing is to find bug.
Let's take a real case to lead you to experience .

One 、 Run code , Find the error .

（ In this step , Understand the prompt to report an error , Generally, compilers are more or less , If you don't understand it, you can assign a value and paste it into CSDN Check to see if anyone has the same error report ）

In this error report , I extracted the entry point ,（ As shown in the above figure, the part with red lines ）.

Two 、 Find the error location .

First, let's see if there are obvious grammatical errors , If you can't see . Try to comment out this part to see if there will be errors （ The key ）.

No obvious mistakes were found , So I tried to comment it out , Be careful not to make mistakes when commenting .（ That is, comment out the root related to this code , Therefore, it also reflects that we should try to integrate the reused code into a function ）.

Associated with what it wants

3、 ... and 、 If the annotation works normally , Then there is an error in the commented part （ This is the most desired result ）;

without , （ Here's the picture , The same mistake , I feel evil ...） So paste the wrong assignment , Search and see

The search results are as follows , It would be best if we found the same , If not ....（ This blogger just doesn't , Dry face ）

However, it seems to be mentioned in these similar results new . At first, I thought the template class was written incorrectly （ After all, the template class is difficult for most heroes ）. Then the whole header file and the corresponding cpp It's annotated （ Later, I found that this idea was wrong , Don't learn from bloggers ）

People are tired of commenting , It's better to sleep for a while and clear your mind . (⊙o⊙)… Get down to business .

Four 、 So I thought it should not be the pot here , Then we will main The start of the call in the function .

First, comment out all , See if there's any more , There is also the compiler problem . Then liberate one by one to find the function in question .

Pictured above , After doing this , Found to be Here's the picture

5、 ... and 、 Generally, compilers have , View definition , Jump to the defined function , To a large extent, this allows us to quickly find bug.

（ Here's the picture ）

6、 ... and 、 Similar to method 5 , Find the problem of calling functions in this function , Or the problem of the function itself

（ Did I mention the called function again here , Therefore, modularization of functions is conducive to our adjustment bug）

7、 ... and 、 Last question , Focus on one if In the sentence

continue

It's inside The problem of two sentences , Then analysis , It is definitely not the fault of the following statement alone , Because if there is no It must be wrong to assign a value when applying for space . And the first sentence has new , Think of the previous search results . I just wonder if new The question of .
First, I tried to become malloc . It turns out , Take a look at this blog and you will know that you can't do this , Also have to new . Why not malloc
After that ？ I thought about it , Since it's right to apply for a space , After applying for space , The assignment of the second statement is wrong . assignment （ Is this sentence very simple ...）, The operation process of assignment is no problem , that , There is only one truth , That's it Used for assignment temp There is a mistake .（ Finally found , That's true ）

8、 ... and 、 Because it's a file stream , I'll try if I read something , Or the file did not open successfully ,

Good guy, if you don't try, you don't know. Try and be surprised . It turned out that the file couldn't be opened （） I'm impressed . This also tells us that we must add a command to check whether the file has been opened .

Nine 、 This analysis is over , I hope that helps