QT比较字符串

Qt中 QString::compare返回值判定：
    int a = QString::compare( "def", "abc" );   // a > 0
    int b = QString::compare( "abc", "def" );   // b < 0
    int c = QString::compare(" abc", "abc" );   // c == 0

最近同学咨询qt的反而事情 忽然想到当年大名湖畔的qt了/。/