📄 sec2-2.htm
字号:
style='font-size:12.0pt;font-family:宋体'>B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>之一为真，则</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A.OR.B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>为真</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal align=left style='margin-left:5.65pt;text-align:left;
line-height:17.0pt;mso-line-height-rule:exactly'><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>为真，则</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>.NOT.A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>为假</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal align=left style='margin-left:5.65pt;text-align:left;
line-height:17.0pt;mso-line-height-rule:exactly'><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>值为同一逻辑常量时，</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A.EQV.B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>为真</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal align=left style='margin-left:5.65pt;text-align:left;
line-height:17.0pt;mso-line-height-rule:exactly'><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的值为不同的逻辑常量，则</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A.NEQV.B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>为真</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
</td>
</tr>
</table>
<p class=MsoNormal style='margin-top:6.0pt;text-indent:24.0pt;mso-char-indent-count:
2.0;line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:
宋体'>注意不要将</span><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>.AND.</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>与</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>.EQV.</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>混淆：</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A.AND.B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>是当</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>均为真时才为真；</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A.EQV.B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>是当</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>均为真或均为假时为真。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p style='tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt'><a
name="第2_2_2c"><span lang=EN-US style='font-family:宋体;color:red'>c)</span></a><span
lang=EN-US style='font-family:宋体;color:red'> </span><span lang=ZH-CN
style='font-family:宋体;color:red'>逻辑表达式的运算</span><span lang=EN-US
style='font-family:宋体;color:red'><o:p></o:p></span></p>
<p class=MsoNormal style='margin-bottom:6.0pt;text-indent:24.0pt;mso-char-indent-count:
2.0;line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:
宋体'>下面是逻辑表达式的例子：</span><span lang=EN-US style='font-size:12.0pt;font-family:
宋体'><o:p></o:p></span></p>
<table class=MsoNormalTable border=1 cellspacing=0 cellpadding=0
style='margin-left:20.9pt;border-collapse:collapse;mso-table-layout-alt:fixed;
border:none;mso-border-alt:solid windowtext .75pt;mso-padding-alt:0cm 1.4pt 0cm 1.4pt'>
<tr style='mso-yfti-irow:0'>
<td width=217 valign=top style='width:163.0pt;border:solid windowtext 1.0pt;
mso-border-alt:solid windowtext .75pt;padding:0cm 1.4pt 0cm 1.4pt'>
<p class=MsoNormal align=center style='text-align:center;line-height:17.0pt;
mso-line-height-rule:exactly'><span lang=ZH-CN style='font-size:12.0pt;
font-family:宋体'>逻辑表达式</span><span lang=EN-US style='font-size:12.0pt;
font-family:宋体'><o:p></o:p></span></p>
</td>
<td width=416 valign=top style='width:11.0cm;border:solid windowtext 1.0pt;
border-left:none;mso-border-left-alt:solid windowtext .75pt;mso-border-alt:
solid windowtext .75pt;padding:0cm 1.4pt 0cm 1.4pt'>
<p class=MsoNormal align=center style='text-align:center;line-height:17.0pt;
mso-line-height-rule:exactly'><span lang=ZH-CN style='font-size:12.0pt;
font-family:宋体'>说明</span><span lang=EN-US style='font-size:12.0pt;font-family:
宋体'><o:p></o:p></span></p>
</td>
</tr>
<tr style='mso-yfti-irow:1;mso-yfti-lastrow:yes'>
<td width=217 valign=top style='width:163.0pt;border:solid windowtext 1.0pt;
border-top:none;mso-border-top-alt:solid windowtext .75pt;mso-border-alt:
solid windowtext .75pt;padding:0cm 1.4pt 0cm 1.4pt'>
<p class=MsoNormal style='margin-left:9.6pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>(A.LT.B).AND.(A.GT.C)<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:9.6pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>(X.LT.0.).OR.(X.GT.100.)<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:9.6pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>.NOT.(X.LE.O.)<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:9.6pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>(A.GT.B).EQV.(C.GT.D)<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:9.6pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=EN-US style='font-size:12.0pt;font-family:宋体'>L1.NEQV.L2<o:p></o:p></span></p>
</td>
<td width=416 valign=top style='width:11.0cm;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
mso-border-top-alt:solid windowtext .75pt;mso-border-left-alt:solid windowtext .75pt;
mso-border-alt:solid windowtext .75pt;padding:0cm 1.4pt 0cm 1.4pt'>
<p class=MsoNormal style='margin-left:12.7pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>当</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>＜</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>B</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>＞</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>C</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>时表达式值为真</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:12.7pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>当</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>X</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>＜</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>0</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>或</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>X</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>＞</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>100</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>时，表达式值为真</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:12.7pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>当</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>X</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>≤</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>0</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>时，表达式值为假</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:12.7pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>当两个括弧内的值都为真或都为假时，表达式的值为真</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:12.7pt;line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>当</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>L1</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>与</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>L2</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>的逻辑值不相同时，表达式的值为真</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
</td>
</tr>
</table>
<p class=MsoNormal style='margin-top:6.0pt;text-indent:24.0pt;mso-char-indent-count:
2.0;line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:
宋体'>一个逻辑表达式中可以包括多个逻辑运算符，如逻辑表达式：</span><span lang=EN-US style='font-size:12.0pt;
font-family:宋体'>A.GE.0.0.AND.A+C.GT.B+D.OR..NOT..TRUE.</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>中不仅有逻辑运算符，还有关系运算符和算术运算符。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>Fortran</span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>规定了以下的运算顺序：</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=EN-US style='font-size:12.0pt;font-family:
宋体'>(1)</span><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>先计算算术表达式的值</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>(</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>例如上式中的</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A+C</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>B+D)</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=EN-US style='font-size:12.0pt;font-family:
宋体'>(2)</span><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>再求关系表达式的值</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>(</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>例如上式中的</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A.LE.0.0</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>A+C.GT.B+D)</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=EN-US style='font-size:12.0pt;font-family:
宋体'>(3)</span><span lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>最后进行逻辑运算，其顺序是：</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'>.NOT. </span><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>＞</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'> .AND. </span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>＞</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'> .OR. </span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>＞</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'> .EQV. </span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>和 </span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>.NEQV.</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>。如果有括弧，则先进行括弧内的运算。</span><span
lang=EN-US style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>
<p class=MsoNormal style='text-indent:24.0pt;mso-char-indent-count:2.0;
line-height:17.0pt;mso-line-height-rule:exactly;tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
mso-char-indent-size:12pt'><span lang=ZH-CN style='font-size:12.0pt;font-family:
宋体'>可用下表表示各种运算符的优先级别：</span><span lang=EN-US style='font-size:12.0pt;
font-family:宋体'><o:p></o:p></span></p>
<table class=MsoNormalTable border=1 cellspacing=0 cellpadding=0
style='margin-left:20.9pt;border-collapse:collapse;border:none;mso-border-alt:
solid windowtext .5pt;mso-padding-alt:0cm 5.4pt 0cm 5.4pt'>
<tr style='mso-yfti-irow:0'>
<td width=102 valign=top style='width:76.55pt;border:solid windowtext 1.0pt;
mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt'>
<p class=MsoNo⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -