sec3-1.htm

Fortran77和90/95编程入门,用于教学

lang=ZH-CN style='mso-font-kerning:0pt'>语句的一些特点是：</span><span lang=EN-US
style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:48.0pt;text-indent:-24.0pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
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mso-char-indent-size:0cm'><![if !supportLists]><span lang=EN-US
style='font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-family:
Symbol;mso-font-kerning:0pt'><span style='mso-list:Ignore'><img width=13
height=13 src="Sec3-1.files/image001.gif" alt="*"><span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=ZH-CN style='mso-font-kerning:0pt'>在上述</span><span
lang=EN-US style='mso-font-kerning:0pt'>DO</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>语句的一般形式中，当循环变量的增量</span><span lang=EN-US
style='mso-font-kerning:0pt'>(</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>步长值</span><span lang=EN-US style='mso-font-kerning:0pt'>)</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>为</span><span lang=EN-US
style='mso-font-kerning:0pt'>1</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>时增量式可不写。</span><span lang=EN-US style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:48.0pt;text-indent:-24.0pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-list:l4 level1 lfo6;tab-stops:45.8pt list 48.0pt left 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:0cm'><![if !supportLists]><span lang=EN-US
style='font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-family:
Symbol;mso-font-kerning:0pt'><span style='mso-list:Ignore'><img width=13
height=13 src="Sec3-1.files/image001.gif" alt="*"><span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=ZH-CN style='mso-font-kerning:0pt'>循环变量初值、终值和步长可以分别是常数、变量或表达式。如果是变量则它应预先被赋值。如果是表达式，则先计算出表达式的值。循环次数可以从循环初值、终值和步长计算出来：次数＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>INT((</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>终值－初值＋增量</span><span lang=EN-US style='mso-font-kerning:
0pt'>)/</span><span lang=ZH-CN style='mso-font-kerning:0pt'>增量</span><span
lang=EN-US style='mso-font-kerning:0pt'>)</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>。如果计算出的循环次数＜</span><span lang=EN-US
style='mso-font-kerning:0pt'>0</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>时，则按</span><span lang=EN-US style='mso-font-kerning:0pt'>0</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>处理，即一次也不执行循环。</span><span lang=EN-US
style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:44.4pt;text-indent:-21.1pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-char-indent-size:0cm'><span lang=ZH-CN style='mso-font-kerning:0pt'>例：对于</span><span
lang=EN-US style='mso-font-kerning:0pt'>D0 I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>1,10,2 </span><span lang=ZH-CN style='mso-font-kerning:0pt'>其循环次数＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>INT((10</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>－</span><span lang=EN-US style='mso-font-kerning:
0pt'>1</span><span lang=ZH-CN style='mso-font-kerning:0pt'>＋</span><span
lang=EN-US style='mso-font-kerning:0pt'>2)</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>／</span><span lang=EN-US style='mso-font-kerning:
0pt'>2)</span><span lang=ZH-CN style='mso-font-kerning:0pt'>＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>5</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>次。</span><span lang=EN-US style='mso-font-kerning:
0pt'>I</span><span lang=ZH-CN style='mso-font-kerning:0pt'>按序分别取值为：</span><span
lang=EN-US style='mso-font-kerning:0pt'>1,3,5,7,9</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>。对于</span><span lang=EN-US style='mso-font-kerning:
0pt'>D0 I</span><span lang=ZH-CN style='mso-font-kerning:0pt'>＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>10,1,2 </span><span lang=ZH-CN
style='mso-font-kerning:0pt'>则循环次数＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>0</span><span lang=ZH-CN style='mso-font-kerning:0pt'>次。</span><span
lang=EN-US style='mso-font-kerning:0pt'>I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>不可取值，程序运行到这里时将跳过此循环。</span><span lang=EN-US
style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:48.0pt;text-indent:-24.0pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-list:l5 level1 lfo8;tab-stops:45.8pt list 48.0pt left 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:0cm'><![if !supportLists]><span lang=EN-US
style='font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-family:
Symbol;mso-font-kerning:0pt'><span style='mso-list:Ignore'><img width=13
height=13 src="Sec3-1.files/image001.gif" alt="*"><span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=ZH-CN style='mso-font-kerning:0pt'>循环变量的初值、终值和步长可以为正或负。初值、终值可以为零。但步长不应为</span><span
lang=EN-US style='mso-font-kerning:0pt'>0</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>，否则循环变量的值永远不会超过终值，从而陷入死循环。</span><span lang=EN-US
style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:44.4pt;text-indent:-21.1pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-char-indent-size:12pt'><span lang=ZH-CN style='mso-font-kerning:0pt'>例：对于</span><span
lang=EN-US style='mso-font-kerning:0pt'>D0 I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>-1,-3,-1 </span><span lang=ZH-CN style='mso-font-kerning:0pt'>其循环次数＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>INT((</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>－</span><span lang=EN-US style='mso-font-kerning:
0pt'>3</span><span lang=ZH-CN style='mso-font-kerning:0pt'>＋</span><span
lang=EN-US style='mso-font-kerning:0pt'>1-1)</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>／</span><span lang=EN-US style='mso-font-kerning:
0pt'>(</span><span lang=ZH-CN style='mso-font-kerning:0pt'>－</span><span
lang=EN-US style='mso-font-kerning:0pt'>1))</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>3</span><span lang=ZH-CN style='mso-font-kerning:0pt'>次。</span><span
lang=EN-US style='mso-font-kerning:0pt'>I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>按序分别取值为：</span><span lang=EN-US style='mso-font-kerning:
0pt'>-1,-2,-3</span><span lang=ZH-CN style='mso-font-kerning:0pt'>。</span><span
lang=EN-US style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:48.0pt;text-indent:-24.0pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-list:l1 level1 lfo10;tab-stops:45.8pt list 48.0pt left 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:0cm'><![if !supportLists]><span lang=EN-US
style='font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-family:
Symbol;mso-font-kerning:0pt'><span style='mso-list:Ignore'><img width=13
height=13 src="Sec3-1.files/image001.gif" alt="*"><span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=ZH-CN style='mso-font-kerning:0pt'>如果循环变量的类型和初值、终值和步长的类型不一致，则按赋值的规则处理，即需先将初值、终值和步长的类型转化成循环变量的类型，然后进行处理。为避免错误，应尽量使循环变量类型与初值、终值和步长的类型一致。</span><span
lang=EN-US style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:44.4pt;text-indent:-21.1pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-char-indent-size:12pt'><span lang=ZH-CN style='mso-font-kerning:0pt'>例：对于</span><span
lang=EN-US style='mso-font-kerning:0pt'>D0 I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>1.5,3.6,1.2 </span><span lang=ZH-CN style='mso-font-kerning:0pt'>不要根据</span><span
lang=EN-US style='mso-font-kerning:0pt'>INT((3.6-1.5</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＋</span><span lang=EN-US style='mso-font-kerning:
0pt'>1.2)/1.2)</span><span lang=ZH-CN style='mso-font-kerning:0pt'>＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>2</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>而认为循环次数为</span><span lang=EN-US style='mso-font-kerning:
0pt'>2</span><span lang=ZH-CN style='mso-font-kerning:0pt'>，而应当先将实型量转化为整型量，即变成相当的循环语句</span><span
lang=EN-US style='mso-font-kerning:0pt'> DO I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>1,3,1 </span><span lang=ZH-CN style='mso-font-kerning:0pt'>其循环次数为</span><span
lang=EN-US style='mso-font-kerning:0pt'>3</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>次而不是</span><span lang=EN-US style='mso-font-kerning:
0pt'>2</span><span lang=ZH-CN style='mso-font-kerning:0pt'>次。</span><span
lang=EN-US style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:44.4pt;text-indent:-21.1pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-char-indent-size:12pt'><span lang=ZH-CN style='mso-font-kerning:0pt'>例：对于</span><span
lang=EN-US style='mso-font-kerning:0pt'>D0 X</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>1.5,3.6,1.2 </span><span lang=ZH-CN style='mso-font-kerning:0pt'>由于循环变量不是整型的而是实型的，它的循环次数为</span><span
lang=EN-US style='mso-font-kerning:0pt'>2</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>次。</span><span lang=EN-US style='mso-font-kerning:
0pt'>X</span><span lang=ZH-CN style='mso-font-kerning:0pt'>取值分别是</span><span
lang=EN-US style='mso-font-kerning:0pt'>1.5,2.7</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>。</span><span lang=EN-US style='mso-font-kerning:
0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:48.0pt;text-indent:-24.0pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-list:l7 level1 lfo12;tab-stops:45.8pt list 48.0pt left 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:0cm'><![if !supportLists]><span lang=EN-US
style='font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-family:
Symbol;mso-font-kerning:0pt'><span style='mso-list:Ignore'><img width=13
height=13 src="Sec3-1.files/image001.gif" alt="*"><span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=ZH-CN style='mso-font-kerning:0pt'>由于实型数在运算和存储时有一些误差，因而循环次数的理论值与实际值之间会有一些差别。这种情况在程序设计中常有发生，而且比较隐蔽不易发现。所以应该避免使用实型的循环变量，用整型循环变量计算出的循环次数是绝对准确的。</span><span
lang=EN-US style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='margin-left:44.4pt;text-indent:-21.1pt;
mso-char-indent-count:0;line-height:17.0pt;mso-line-height-rule:exactly;
mso-char-indent-size:12pt'><span lang=ZH-CN style='mso-font-kerning:0pt'>例：对于</span><span
lang=EN-US style='mso-font-kerning:0pt'>D0 X</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>0.0,50.0,0.1</span><span lang=ZH-CN style='mso-font-kerning:0pt'>理论循环次数＝</span><span
lang=EN-US style='mso-font-kerning:0pt'>INT(50.1/0.1)</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>501</span><span lang=ZH-CN style='mso-font-kerning:0pt'>，但实际上在许多计算机上它只执行</span><span
lang=EN-US style='mso-font-kerning:0pt'>500</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>次循环。原因是实数在内存中的误差使得增量值不是准确的</span><span lang=EN-US
style='mso-font-kerning:0pt'>0.1</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>，由于循环的误差积累，到执行完</span><span lang=EN-US style='mso-font-kerning:0pt'>500</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>次循环后</span><span lang=EN-US
style='mso-font-kerning:0pt'>X</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>的值可能已超过</span><span lang=EN-US style='mso-font-kerning:0pt'>50.O</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>，因而停止执行循环。改用整型循环变量时，则循环改写为：</span><span
lang=EN-US style='mso-font-kerning:0pt'>D0 I</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>＝</span><span lang=EN-US style='mso-font-kerning:
0pt'>0,500</span><span lang=ZH-CN style='mso-font-kerning:0pt'>；</span><span
lang=EN-US style='mso-font-kerning:0pt'> X=I/10</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>。</span><span lang=EN-US style='mso-font-kerning:
0pt'><o:p></o:p></span></p>

<p style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l10 level1 lfo2;
tab-stops:list 18.0pt'><a name="第3_1_2b"></a><![if !supportLists]><span
lang=EN-US style='font-family:宋体;mso-bidi-font-family:宋体;color:red'><span
style='mso-list:Ignore'>b)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=EN-US style='font-family:宋体;
color:red'>DO</span><span lang=ZH-CN style='font-family:宋体;color:red'>循环执行步骤</span><span
lang=EN-US style='font-family:宋体;color:red'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='mso-font-kerning:0pt'>循环执行过程按序为以下几个步骤：</span><span
lang=EN-US style='mso-font-kerning:0pt'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(1).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>计算初值式、终值式、增量式的值，并将它们转换成循环变量的类型。</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:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(2).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>将初值赋予循环变量。</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:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(3).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>计算应循环的次数。</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:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(4).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>检查循环次数，若≤</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'>则跳过循环体，执行循环终端语句下面的一个执行语句。如果＞</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'>，则执行循环体。</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'><o:p></o:p></span></p>

<p class=MsoNormal style='margin-left:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(5).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>执行终端语句时，循环变量增值。</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:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(6).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>循环次数减</span><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'>。</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:63.8pt;text-indent:-24.0pt;line-height:
17.0pt;mso-line-height-rule:exactly;mso-list:l2 level2 lfo14;tab-stops:list 63.8pt 78.0pt'><![if !supportLists]><span
lang=EN-US style='font-size:12.0pt;font-family:宋体;mso-bidi-font-family:宋体;
color:black'><span style='mso-list:Ignore'>(7).</span></span><![endif]><span
lang=ZH-CN style='font-size:12.0pt;font-family:宋体'>返回</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>(4)</span><span lang=ZH-CN
style='font-size:12.0pt;font-family:宋体'>，重复执行</span><span lang=EN-US
style='font-size:12.0pt;font-family:宋体'>(4)</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'>(5)</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'>(6)</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'>(7)</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 style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l10 level1 lfo2;
tab-stops:list 18.0pt'><a name="第3_1_2c"></a><![if !supportLists]><span
lang=EN-US style='font-family:宋体;mso-bidi-font-family:宋体;color:red'><span
style='mso-list:Ignore'>c)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span lang=ZH-CN style='font-family:宋体;
color:red'>循环终端语句</span><span lang=EN-US style='font-family:宋体;color:red'><o:p></o:p></span></p>

<p class=MsoBodyTextIndent2 style='line-height:17.0pt;mso-line-height-rule:
exactly'><span lang=ZH-CN style='mso-font-kerning:0pt'>上面介绍的循环中，循环终端语句为一般的执行语句。</span><span
lang=EN-US style='mso-font-kerning:0pt'>F90</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>规定：循环终端语句可以是除了</span><span lang=EN-US
style='mso-font-kerning:0pt'>GOTO</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>、块</span><span lang=EN-US style='mso-font-kerning:0pt'>IF</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>、</span><span lang=EN-US
style='mso-font-kerning:0pt'>CASE</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>、</span><span lang=EN-US style='mso-font-kerning:0pt'>CYCLE</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>、</span><span lang=EN-US
style='mso-font-kerning:0pt'>DO</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>、</span><span lang=EN-US style='mso-font-kerning:0pt'>ELSE</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>、</span><span lang=EN-US
style='mso-font-kerning:0pt'>ELSE IF</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>、</span><span lang=EN-US style='mso-font-kerning:0pt'>END IF</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>、</span><span lang=EN-US
style='mso-font-kerning:0pt'>END</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>、</span><span lang=EN-US style='mso-font-kerning:0pt'>END SELECT</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>、</span><span lang=EN-US
style='mso-font-kerning:0pt'>EXIT</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>、</span><span lang=EN-US style='mso-font-kerning:0pt'>SELECT CASE</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>、</span><span lang=EN-US
style='mso-font-kerning:0pt'>STOP</span><span lang=ZH-CN style='mso-font-kerning:
0pt'>和</span><span lang=EN-US style='mso-font-kerning:0pt'>RETURN</span><span
lang=ZH-CN style='mso-font-kerning:0pt'>语句以外的任一可执行语句，如打印语句、赋值语句、输入语句、逻辑</span><span
lang=EN-US style='mso-font-kerning:0pt'>IF</span><span lang=ZH-CN
style='mso-font-kerning:0pt'>语句等都可以作为终端语句。特殊的