Is it possible to use std::sort defined inside <algorithm> for sorting char arrays according to their ASCII value? If yes, please provide an example.
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what you want is basically an "alphabetically sorted array" the ASCII value is use for the "standard" way of ordering chars in C and C++, for example a is < than b because of its own ASCII value.user1824407– user18244072013-01-01 15:59:00 +00:00Commented Jan 1, 2013 at 15:59
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5 Answers
Yes. That is definitely possible. You could know that just by writing some sample code, such as this:
char charArray[] = {'A','Z', 'K', 'L' };
size_t arraySize = sizeof(charArray)/sizeof(*charArray);
std::sort(charArray, charArray+arraySize);
//print charArray : it will print all chars in ascending order.
By the way, you should avoid using c-style arrays, and should prefer using std::array or std::vector.
std::array is used when you know the size at compile-time itself, while std::vector is used when you need dynamic array whose size will be known at runtime.
2 Comments
Harish Vishwakarma
Thanks, would it work in the same work for string as well? And can you also take a look at my other question, here stackoverflow.com/questions/14078889/…
0x5453
Instead of
sizeof(charArray)/sizeof(*charArray) you can just use std::size(charArray).Yes:
char array[] = "zabgqkzg";
std::sort(array, array+sizeof(array));
See http://ideone.com/0TkfDn for a working demo.
answered Jan 1, 2013 at 15:59
Oliver Charlesworth
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2 Comments
Harish Vishwakarma
Can you also take a look at my other problem? Here, stackoverflow.com/questions/14078889/…
d3r0n
Size -1 or You will sort with the null. std::sort(array, array+sizeof(array)-1);
The proper way is, of course, to use std::begin() and std::end():
std::sort(std::begin(array), std::end(array));
If you don't have a C++ 2011 compiler, you can implement corresponding begin() and end() functions, e.g.:
template <typename T, int Size>
T* end(T (&array)[Size]) {
return array + Size;
}
3 Comments
Harish Vishwakarma
Thanks. So begin and end are defined in C++ 2011 compiler and not before that?
Dietmar Kühl
Yes (although they are part of the library; I thing they are declared in
<iterator>). However, they are easy to define.Harish Vishwakarma
K. Please take a look to an another question by me,here stackoverflow.com/questions/14078889/…
Answers using sizeof(charArray) assume that the array must be completely filled. When ran using partially filled array, they produce garbage results.
In that case use:
sort(str, str + strlen(str));
Comments
I just use this and answered for me.
char name[9] = "zxcda";
int length = 0;
for(int i=0;name[i]!='\0';i++)
length++;
sort(name , name+length);
cout << name;
