C ++的错误 - 返回字符数组 [英] C++ error - returning a char array

问题描述

考虑以下code：

char CeaserCrypt(char str[256],int key)
{
    char encrypted[256],encryptedChar;
    int currentAsci;

    encrypted[0] = '\0'; 

    for(int i = 0; i < strlen(str); i++) 
    {
        currentAsci = (int)str[i];
        encryptedChar = (char)(currentAsci+key);
        encrypted[i] = encryptedChar;
    }

    return encrypted;
}

Visual Studio 2010中，因为该函数返回一个数组给出了一个错误。我应该怎么办？

Visual Studio 2010 gives an error because the function returns an array. What should I do?

我的朋友告诉我改签名，以无效CeaserCrypt（加密字符海峡[256]，CHAR [256]，INT键）。但我不认为这是正确的。我怎样才能摆脱编译错误的？

My friend told me to change the signature to void CeaserCrypt(char str[256], char encrypted[256], int key). But I don't think that is correct. How can I get rid of the compile error?

推荐答案

的返回类型应该是的char * 但这只会增加的另一个问题。

The return type should be char * but this'll only add another problem.

加密是 CeaserCrypt 的堆栈的分配，并可能不是当函数返回时有效。由于加密将具有相同长度的输入，这样做：

encrypted is "allocated" on the stack of CeaserCrypt and might not be valid when the function returns. Since encrypted would have the same length as the input, do:

int len = strlen(str);
char *encrypted = (char *) malloc(len+1);

encrypted[len] = '\0';

for (int i = 0; i < len; i++) {
// ...
}

不要忘了以后释放缓冲区，但（与免费（））。

编辑： @Yosy：不觉得有义务只是复制/粘贴。使用此作为的指针的提高你的编码实践。此外，为了满足批评家：使用上述已经分配的指针传递给你的加密例程的例如的

@Yosy: don't feel obliged to just copy/paste. Use this as a pointer to improve your coding practice. Also, to satisfy criticizers: pass an already allocated pointer to your encryption routine using the above example.

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