INFO: qsort() Can Sort Data Structures Based on Multiple Fields (28244)


The information in this article applies to:

  • The C Run-Time (CRT), when used with:
    • Microsoft C for MS-DOS
    • Microsoft C for OS/2
    • Microsoft Visual C++ for Windows, 16-bit edition 1.0
    • Microsoft Visual C++ for Windows, 16-bit edition 1.5
    • Microsoft Visual C++, 32-bit Editions 1.0
    • Microsoft Visual C++, 32-bit Editions 2.0
    • Microsoft Visual C++, 32-bit Editions 4.0
    • Microsoft Visual C++, 32-bit Editions 5.0
    • Microsoft Visual C++, 32-bit Editions 6.0
This article was previously published under Q28244

SUMMARY

The qsort() function in the Microsoft C run-time library does not restrict the methods an application can use to compare items. When qsort() compares two data elements, it calls an application-supplied comparison routine.

To sort an array of structures using more than one field as a key, create a comparison function that relates the appropriate fields in each structure and returns a comparison value to indicate the result.
Modification Type:MinorLast Reviewed:7/5/2005
Keywords:kbCRT kbinfo KB28244
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