String series in practice c ++ -- do not use memset to initialize string (do not do this)

String series in practice c ++ -- do not use memset to initialize string (do not do this)

Baidu encyclopedia was so powerful for the first time:

Void * memset (void * s, int ch, size_t n );
Function explanation: Replace the first n Bytes (typedef unsigned int size_t) in s with ch and return s.
Memset: fills in a given value in a memory block. It is the fastest way to perform the clearing operation on a large struct or array.

Memset () functions are often used for memory space initialization:
　

　char str[100];　memset(str,0,100);

It is used to set all memory space to a specific character. It is generally used to initialize the defined string'

memset(a, '\0', sizeof(a));

Memcpy is used for memory copying. You can use it to copy any data type object. You can specify the length of the copied data:

Char a [100], B [50]; memcpy (B, a, sizeof (B); // If sizeof (a) is used ), b's memory address overflows.

Strcpy can only copy strings. when it encounters '\ 0', it ends the copy:
　　

char a[100], b[50];strcpy(a,b);

For example, if strcpy (B, a) is used, check whether the length of the string in a (before the first '\ 0') exceeds 50 bits. If it exceeds, this will cause memory address overflow of B.
　　

Start as follows:

class Material{public:    Material(){ setDefaults();}    void setDefaults(){ memset(this,0,sizeof(*this));}    int mark;    char materialName[256]; // material name    Vector3 ambient;    // ambient    Vector3 diffuse;    // diffuse    Vector3 specular;   // specular    int shininess;  //    float alpha;    //    bool isSpecular;char textureName[256];  // texture namechar textureTransName[256]; // transparent texture name};

This code is flawless. Let's take a look at the following:

class Material{public:    Material(){ setDefaults();}    void setDefaults(){ memset(this,0,sizeof(*this));}    int mark;    std::string materialName;   // material name    Vector3 ambient;    // ambient    Vector3 diffuse;    // diffuse    Vector3 specular;   // specular    int shininess;  //    float alpha;    //    bool isSpecular;std::string textureName;    // texture namestd::string textureTransName;   // transparent texture name};

The above code may cause memory leakage:
Therefore, for C ++ std: string, C ++-style Initialization is required.

When I see such a comment on the internet, I think it makes sense:
No memset can be used for any class. Once it is violent, it means that you have raped her internal data, and she has crashed.