C++ 使用了未初始化的局部变量“j”
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uninitialized local variable 'j' used
提问by user2371621
Here is a section of some code I have. Im getting an error uninitialized local variable 'j' used and I dont see it. as far as I can tell it is being used. Can someone please help?
这是我拥有的一些代码的一部分。我收到错误未初始化的局部变量“j”，但我没有看到。据我所知，它正在被使用。有人可以帮忙吗？
float Calculate(Element ElmAry[30], Formula FormAry[30])
{
int i;
int j;
float MoleWT = 0;
float MoleSum = 0;
char e1;
char e2;
char f1;
char f2;
for(i = 0; i < 30; i++) {
f1 = FormAry[j].Element1;
f2 = FormAry[j].ElementA;
e1 = ElmAry[i].eN1;
e2 = ElmAry[i].eN1;
if(e1 == f1 && e2 == f2) {
MoleWT = ElmAry[i].Weight * FormAry[j].Atom;
MoleSum = MoleSum + MoleWT;
j++;
}
}
return MoleSum;
}
回答by xbonez
You haven't given ja value, hence the uninitialized variableerror.
您没有给出j值，因此出现uninitialized variable错误。
int j;is not the same as assigning ja value of 0.
int j;与赋值j0 不同。
You should do: int j = 0;
你应该做： int j = 0;
回答by nhgrif
The error isn't that jis being used. The error is that jis being used but it isn't being initialized.
错误不是j正在使用。错误是j正在使用但未初始化。
I suggest changing your forloop to:
我建议将您的for循环更改为：
for(i=0, j=0; i < 30; i++, j++)
As I think this is probably what you're actually trying to do...
因为我认为这可能是你真正想要做的......
回答by justhalf
So you use the variable jfirst in the line
所以你j首先在行中使用变量
f1 = FormAry[j].Element1;
But you haven't assigned any value to jpreviously, hence "uninitialized". The previous mention of jwas in your declaration:
但是您之前没有分配任何值j，因此“未初始化”。之前提到的j是在您的声明中：
int j;
You need to assign a value to it, like 0:
您需要为其分配一个值，例如 0：
int j = 0;
That is call "initialization", because if you don't assign any value to a variable, what value should you expect from that variable?
这就是所谓的“初始化”，因为如果你不给一个变量赋值，你应该从那个变量中得到什么值？
