1-D MEMORY ALLOCATION IN C & C++

1-D MEMORY ALLOCATION IN C :-  


1. All pointers in C & C++ is of 4 Bytes on 32 Bit system.
2. In C, Dynamic Memory Allocation is done by malloc( ), calloc( ), realloc( ) & free ( ). 
3. malloc( ) takes only single arguement ( the amount of memory to allocate in bytes ). 
4. malloc( ) does not initialize the memory allocated, they contains garbage values.
5. calloc( ) needs two arguements ( the no. of variables to allocate in memory, & the size in bytes  of single variable ).
6. calloc( ) initialize the allocated memory by Zero.
7. free( ) is used to free all the allocated memory which is allocated by the pointer at the time of execution.              



(1). char Array.

char* nameofarray = (char*)malloc( memorywanttoallocate * sizeof(char*) ); 
free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

(2). int Array.


int* nameofarray = (int*)malloc( memorywanttoallocate * sizeof(int*));

free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

(3). float Array.

float* nameofarray = (float*)malloc(memorywanttoallocate * sizeof(float*));
free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

(4). double Array.



double* nameofarray = (double*)malloc(memorywanttoallocate * sizeof(double*));

free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

2-D MEMORY ALLOCATION IN C :-

(1). char Array.

char** nameofarray = (char**)malloc( HeightofMatrix * sizeof(char**) );
for( int i = 0; i < HeightofMatrix; i++ )
{
     nameofarray[ i ] = (char*)malloc( WidthofMatrix * sizeof(char*));
}
free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

(2). int Array.

int** nameofarray = (int**)malloc( HeightofArray * sizeof(int**));

for( int i = 0; i < HeightofMatrix; i++ )
{
     nameofarray[ i ] = (int*)malloc( WidthofMatrix * sizeof(int*));
}
free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

(3). float Array.

float** nameofarray = (float**)malloc( * sizeof(float**));

for( int i = 0; i < HeightofMatrix; i++ )
{
     nameofarray[ i ] = (float*)malloc( WidthofMatrix * sizeof(float*));
}

free(nameofarray);  // this line will free all memory that is allocated by malloc( ). 

(4). double Array.



double** nameofarray = (double**)malloc(memorywanttoallocate * sizeof(double*));

for( int i = 0; i < HeightofMatrix; i++ )
{
     nameofarray[ i ] = (double*)malloc( WidthofMatrix * sizeof(double*));
}

free(nameofarray);  // this line will free all memory that is allocated by malloc( ).