检查日期是否与PHP连续

Question

如何在此字符串中检查日期是否连续？

$dates = "2017-01-08, 2017-01-09, 2017-01-10";

对于此示例，3个日期是连续的。

$dates = "2017-01-08, 2017-01-12, 2017-01-13";

对于此示例，3个日期不是连续的。

对此有何帮助？

感谢。

Answer 1

使用DateTime::diff功能，您可以获得天数差异。然后遍历日期，如果差异不是一天，则不是连续的。

$dates = "2017-01-08, 2017-01-09, 2017-01-10";
var_dump(check_continuous_dates($dates)); // true

$dates = "2017-01-08, 2017-01-12, 2017-01-13";
var_dump(check_continuous_dates($dates)); // false

function check_continuous_dates($date) {
    $date = explode(", ", $date); // Convert it to an array we can loop
    $previous = new DateTime($date[0]); // Set the "previous" value
    unset($date[0]); // Unset the value we just set to $previous, so we don't loop it twice

    foreach ($date as $v) { // Loop the array
        $current = new DateTime($v);
        $diff = $current->diff($previous);

        // If the difference is exactly 1 day, it's continuous 
        if ($diff->days == 1) {
            $previous =  new DateTime($v);
        } else {
            return false;
        }
    }
    return true;
}

Demo

参考

• http://php.net/manual/en/datetime.diff.php

Answer 2

ArrayList<String> arrTblNames = new ArrayList<>();
    List<List<String>> data = new ArrayList<>();

    Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);

    if (c.moveToFirst()) {
        while ( !c.isAfterLast() ) {
            arrTblNames.add( c.getString( c.getColumnIndex("name")) );
            c.moveToNext();
        }
    }
    for(int i=0; i<=arrTblNames.size()-1;i++){
        Cursor dbCursor = db.query(arrTblNames.get(i), null, null, null, null, null, null);
        String[] columnNames = dbCursor.getColumnNames();
        Cursor c2 = db.query(arrTblNames.get(i),columnNames,null,null,null,null,null);
        if (c2.moveToFirst()) {
            while ( !c2.isAfterLast() ) {
                data.add(new ArrayList<String>());
                for(int j=0; j<=columnNames.length-1;j++){
                    data.get(i).add( c2.getString( c2.getColumnIndex(columnNames[j])) );
                }
                c2.moveToNext();
            }
        }
    }