[C Language] Data Structure-preparation knowledge cross-Function Memory, data structure preparation

[C Language] Data Structure-preparation knowledge cross-Function Memory, data structure preparation

Memory usage across functions

When a function stops running, the memory allocated by the malloc function will not be released if free is not called.

You can continue to use this function in another function.

# Include

# Include

// Memory usage across functions

// Transmits the struct pointer, occupying less memory

Struct Student {

Int age;

Int score;

Char * name;

};

Struct Student * createStudent (struct Student *); // pre-Statement

Void showStudent (struct Student *);

Int main (void ){

Struct Student * pst; // defined. Currently, only four bytes are occupied.

Pst = createStudent (pst); // create and allocate memory

ShowStudent (pst); // display, continue to use the above memory

}

Struct Student * createStudent (struct Student * pst ){

Pst = (struct Student *) malloc (sizeof (struct Student); // allocates memory for this struct and returns a pointer

Pst-> age = 100; // assign values to struct members

Pst-> score = 9999;

Pst-> name = "taoshihan ";

Return pst;

}

Void showStudent (struct Student * pst ){

// Continue to use the memory allocated in the above function

Printf ("% s = % d", pst-> name, pst-> age, pst-> score );

}