can any one show me the proper path do this

[kishore84]

Hello friends,

I have arr of int , now i want to save it in a memory allocated in heap and But the memory will be of type char* with comma in betn them.

I mean finally i want the data in below format

char * str = "100,101,102,103"
can any one guide me how to do that in a simplest way.


Thanks

[kishore84]

if the query is not clear.please let me know.



Thanks

[vmpstr]

assuming that you allocate enough space to the char*, you can use sprintf in a loop

you want to initialize your str to an empty string, and then keep printing to the end of it. You know the end of the string with either strlen or some calculation using sprintf's return code.

In my opinion that would be as simple as any other approach

[donbock]

How big does this heap allocation need to be? Look at <limits.h> to see the maximum number of digits for the appropriate integer type. typically, the number of characters needed corresponds to the minimum value due to the negative sign. Let's call the characters needed for one integer 'C'. Looks like you want a comma separator between each value. You also need a null terminator at the end of the string.

For N integers, a heap buffer guaranteed to hold a string representation of the integers is N*(C+1).

Even if this size allocation is "guaranteed" to be big enough, it is still good practice to include error checking code to prevent you from writing past the end of the heap buffer. Also, don't forget to verify that the heap allocation succeeded.

This suggestion requires you to examine <limits.h> to count the number of digits in INT_MIN, and hard code that count into your program. Can you think of way to write your program so that it automatically adapts to changes in <limits.h> if you recompile it on other platforms? That's the essence of writing portable software.

[weaknessforcats]

Don't overlook using itoa() and strcat().