C Dynamic Memory Allocation - Usage Example

Usage Example

The standard method of creating an array of 10 int objects:

int array;

However, if one wishes to allocate a similar array dynamically, the following code could be used:

/* Allocate space for an array with ten elements of type int. */ int *ptr = (int *) malloc(10 * sizeof(int)); if (NULL == ptr) { /* Memory could not be allocated. The program should handle the error here as appropriate. */ } else { /* Allocation succeeded. Do something with it... */ /* We are done with the array of ints, and can free the block of memory */ free(ptr); /* The pointed-to address must not be used again, unless re-assigned by another call to malloc. */ ptr = NULL; }

malloc returns a null pointer to indicate that no memory is available, or that some other error occurred which prevented memory being allocated.

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