Thread: (float) or (float*) wrt sizeOf()

I keep seeing these calls when allocating memory and its confusing the **** out of me. Please can someone clarify for me.

Here are the two calls that are confusing me.

malloc(arraySizeX*sizeof(float*))
malloc(arraySizeX*sizeof(float))

Whats the difference between
sizeof(float*)
and
sizeof(float)

More precisely what affect does the * symbol have on the parameter float?

Not sure if Its a typo I keep seeing pop up when I see this function used (mostly in malloc() calls) or if these two calls have different results?
Thank you.

More precisely what affect does the * symbol have on the parameter float?

The * symbol is representative of the pointer in C.
A pointer is basically a variable which holds the address of another variable in the program.\

eg:

Code:

float x = 5.0;
float* px = &x;// & is the address of operator which returns the address of x
printf("The variable x = %f lives at the adress %p",*px, px);//*px dereferences the pointer and returns the value the pointer is pointing to

a pointer is usually 4 bytes in memory.

in your example

Code:

malloc(arraySizeX*sizeof(float*))

is usually used when allocating memory to a pointer to a pointer or perhaps a 2D array.

and

Code:

malloc(arraySizeX*sizeof(float)

is used when allocating memory for a pointer, or in your case and array.

Awesome. That cleared it up. Thank you for the help.