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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><!-- Constants --><HTML><HEAD><TITLE>Constants</TITLE></HEAD><BODY BACKGROUND="spiral.gif" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#990099" ALINK="#FF0000"><TABLE WIDTH="98%"><TR><TD WIDTH=60 VALIGN=BOTTOM NOWRAP><IMG SRC="transp.gif" ALT="" WIDTH=60 HEIGHT=20></TD><TD><!-- Ab hier Seitentext: --><BIG><BR><P><STRONG><U>III.3 Constants</U></STRONG></P><P>Numeric constants consist of a sequence of digits, followed by a radixspecifier. The first character must always be a decimal digit.The legal digits and radix specifiers are:</P><P><BLOCKQUOTE><TABLE BORDER CELLPADDING=8><TR><TH>constant</TH><TH>digits </TH><TH>radix </TH></TR><TR><TD>binary </TD><TD NOWRAP>0 ... 1</TD><TD NOWRAP>B </TD></TR><TR><TD>octal </TD><TD NOWRAP>0 ... 7</TD><TD NOWRAP>Q or O </TD></TR><TR><TD>decimal </TD><TD NOWRAP>0 ... 9</TD><TD NOWRAP>D or none</TD></TR><TR><TD>hex </TD><TD NOWRAP>0 ... F</TD><TD NOWRAP>H </TD></TR></TABLE></BLOCKQUOTE></P><P>Thus, for example, the following constants are equivalent:</P><P><BLOCKQUOTE><PRE>1111111B binary 177Q octal 177o octal 127 decimal 127d decimal 07FH hex</PRE></BLOCKQUOTE></P><P>Character constants may be used wherever a numeric value is allowed.A character constant consists of one or two printing characters enclosedin single or double quotes. The quote character itself can be representedby two subsequent quotes. For example:</P><P><BLOCKQUOTE><PRE> 'X' 8 bit constant: 58H"a@" 16 bit constant: 6140H'''' 8 bit constant: 27H</PRE></BLOCKQUOTE></P><P>In DB statements, character constants may have any length.In this case, we call it a character string. For example:</P><P><BLOCKQUOTE><PRE>'This is only text!'</PRE></BLOCKQUOTE></P></BIG><!-- Seitentext Ende --><P><BR><BR><CENTER><TABLE WIDTH="70%"><TR><TH><A HREF="contents.htm"><IMG SRC="home.gif" ALT="[contents]" BORDER=0 WIDTH=32 HEIGHT=32></A></TH> <TH><A HREF="language.htm"><IMG SRC="up.gif" ALT="[up]" BORDER=0 WIDTH=32 HEIGHT=32></A></TH> <TH><A HREF="symbols.htm"><IMG SRC="back.gif" ALT="[back]" BORDER=0 WIDTH=32 HEIGHT=32></A></TH> <TH><A HREF="express.htm"><IMG SRC="next.gif" ALT="[next]" BORDER=0 WIDTH=32 HEIGHT=32></A></TH></TR></TABLE></CENTER></P></TD></TR></TABLE></BODY></HTML>⌨️ 快捷键说明
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