Free () function in C

The void free function (void * ptr) frees the previously allocated memory by a call to calloc, malloc, or realloc

Declare the free () function in C

Below is the declaration for free () in C:

 void  free ( void * ptr ) 

Parameters

ptr : This is the pointer to the previously allocated memory block with malloc, calloc or realloc to be freed. If the input parameter is a null pointer, no action will take place.

Returns the value

This function does not return any values.

For example

The following C program illustrates the usage of free () in C:

 #include #include #include int  main () { char * str ; /* lan cap phat bo nho ban bau */  str  = ( char *)  malloc ( 15 );  strcpy ( str , "QTMTeam" );  printf ( "Chuoi = %s, tai Dia chi = %un" ,  str ,  str ); /* tai cap phat lai bo nho */  str  = ( char *)  realloc ( str , 25 );  strcat ( str , ".@gmail.com" );  printf ( "Chuoi = %s, tai Dia chi = %un" ,  str ,  str ); /* Giai phong bo nho da cap phat */  free ( str ); return ( 0 ); } 

Compile and run the above C program to see the results.

According to Tutorialspoint

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