What is the use of this Function

[Rahulbatra]

I want to know the use of qsort function in C programming language. Is this used for sorting elements as the name implies.

[zsk_00]

also called quick-sort, yes it is one of the sorting (a rather expensive one) method

[Sandhya.Kishannag]

qsort() is standard C function for sorting arrays. It is defined by ISO C standard, and implemented in most C/C++ standard libraries(stdlib.h)

qsort() takes four arguments:

void qsort(void *base, size_t nel, size_t width, int (*compar)(const void *, const void *));

* base — is a pointer to the beginning of data array
* nel — is a number of elements
* width — is a size of each element (in bytes)
* compar — is a callback function (pointer to function), which does comparison and returns positive or negative integer depending on result.

[webcurious]

This explanation of qsort definitely helps. The explanation of base, nel, width, compar, is also very handy. It's amazing what just a little teaching can do for a beginning programming student.