Size of objects in Memory

Quote:

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it works, but i need to know how to get ride of those errors before i can go any further. As i if i get a char array it will be fine, but it won't always be a char array

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C is a type strict language. I am not responsible if you try to use a function built for C strings on an array of a different type. Which is the extent of your problem. In C, "4" is not 4. Resist your Pythonic background.

To calculate the size of a local array of some type sizeof a will work. If you think about it both the size of the pointer and the array's individual elements will be known at compile time. The exception is heap memory, where you will always end up with the size of a pointer (simply because that is how it is accessed). Then you have to do a run time calculation such as

length * sizeof( *p )

like what you did for malloc: p's net load on your RAM.

great, i should be all set from here

thank you

You're very welcome.

Quote:

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Originally Posted by Doorsdown

the 152 bytes is because its of type double, i would expect that.

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Yes I also would expect that 8 * 19 will give a result of 152

but this number has nothing to do with the actually allocated size in the memory, because the 8 has nothing to do with the size of the array member...

Quote:

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Originally Posted by vart

Yes I also would expect that 8 * 19 will give a result of 152

but this number has nothing to do with the actually allocated size in the memory, because the 8 has nothing to do with the size of the array member...

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i fixed that, it was seeing the 0 and using it as a null terminator, it now shows

Code:

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Key is 23 long and its type is 8 big
Key is 184 bytes.

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Quote:

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Originally Posted by Doorsdown

Code:

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09      double *key;
10      int size = 0;
11      key = "149186491491496146\n";
12      size = strlen(key) * sizeof(key[0]);
13      printf("Key is equal to %s and its %i bytes.\n",key,size);

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outputs

Code:

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memory.c: In function 'main':
memory.c:11: warning: assignment from incompatible pointer type
memory.c:12: warning: passing argument 1 of 'strlen' from incompatible pointer type
Key is equal to 149186491491496146
 and its 152 bytes.

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it works, but i need to know how to get ride of those errors before i can go any further. As i if i get a char array it will be fine, but it won't always be a char array

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These warnings are due to type mismatch.
1)What u r doing is, u have taken a double type pointer *key. and assigning a character string into it.
2)Signature of strlen is "size_t strlen(const char *s)". And u r paasing adouble type pointer in it.

Use proper type casting.