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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <title>page_505</title> <link rel="stylesheet" href="reset.css" type="text/css" media="all"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head> <body> <table summary="top nav" border="0" width="100%"> <tr> <td align="left" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_504.html">< previous page</a></td> <td align="center" width="40%" style="background: #EEF3E2"><strong style="color: #2F4F4F; font-size: 120%;">page_505</strong></td> <td align="right" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_506.html">next page ></a></td> </tr> <tr> <td align="left" colspan="3" style="background: #ffffff; padding: 20px;"> <table border="0" width="100%" cellpadding="0"><tr><td align="center"> <table border="0" cellpadding="2" cellspacing="0" width="100%"><tr><td align="left"></td> <td align="right"></td> </tr></table></td></tr><tr><td align="left"><p></p><table border="0" cellspacing="0" cellpadding="0" width="100%"><tr><td align="right"><font face="Times New Roman, Times, Serif" size="2" color="#FF0000">Page 505</font></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td> <td colspan="3" height="12"></td> <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td> <td><font face="Times New Roman, Times, Serif" size="3">header file defines the constants </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">CHAR_MAX</font><font face="Times New Roman, Times, Serif" size="3"> and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">CHAR_MIN</font><font face="Times New Roman, Times, Serif" size="3">, </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">SHRT_MAX</font><font face="Times New Roman, Times, Serif" size="3"> and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">SHRT_MIN</font><font face="Times New Roman, Times, Serif" size="3">, </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">INT_MAX</font><font face="Times New Roman, Times, Serif" size="3"> and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">INT_MIN</font><font face="Times New Roman, Times, Serif" size="3">, and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">LONG_MAX</font><font face="Times New Roman, Times, Serif" size="3"> and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">LONG_MIN</font><font face="Times New Roman, Times, Serif" size="3">. The unsigned types have a minimum value of zero and maximum values defined by </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">UCHAR_MAX</font><font face="Times New Roman, Times, Serif" size="3">, </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">USHRT_MAX</font><font face="Times New Roman, Times, Serif" size="3">, </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">UINT_MAX</font><font face="Times New Roman, Times, Serif" size="3">, and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">ULONG_MAX</font><font face="Times New Roman, Times, Serif" size="3">. To find out the values specific to your computer you could print them out like this:</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td> <td colspan="3" height="12"></td> <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td> <td><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">#include聽<limits.h><br />.<br />.<br />.<br />cout聽<聽Max.聽long聽=聽聽<聽LONG_MAX聽<聽endl;<br />cout聽<聽Min.聽long聽=聽聽<聽LONG_MIN聽<聽endl;<br />.<br />.<br />.</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td> <td colspan="3" height="12"></td> <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td> <td><font face="Times New Roman, Times, Serif" size="3">Constants</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td> <td colspan="3" height="12"></td> <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td> <td><font face="Times New Roman, Times, Serif" size="3">In C++, integer constants can be specified in three different number bases: decimal (base-10), octal (base-8), and hexadecimal (base-16). Just as the decimal number system has 10 digits0 through 9the octal system has 8 digits0 through 7. The hexadecimal system has digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F, which correspond to the decimal values 0 through 15. Octal and hexadecimal values are used in system software (compilers, linkers, and operating systems, for example) to refer directly to individual bits in a memory cell and to control hardware devices. These manipulations of low-level objects in a computer are the subject of more advanced study and are outside the scope of this book.</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td> <td colspan="3" height="12"></td> <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td> <td><font face="Times New Roman, Times, Serif" size="3">The following table shows examples of integer constants in C++. Notice that an </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">L</font><font face="Times New Roman, Times, Serif" size="3"> or </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">U</font><font face="Times New Roman, Times, Serif" size="3"> (either uppercase or lowercase) can be added to the end of a constant to signify </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">long</font><font face="Times New Roman, Times, Serif" size="3"> or </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">unsigned</font><font face="Times New Roman, Times, Serif" size="3">, respectively.</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table cellpadding="0" cellspacing="0" border="0" width="100%"><tr><td height="12"></td></tr><tr><td><table cellspacing="0" width="528" cellpadding="7"><tr><td valign="top"><font face="Times New Roman, Times, Serif" size="2"><i>Constant</i></font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2"><i>Type</i></font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2"><i>Remarks</i></font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">1658</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">int</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Decimal (base-10) integer.</font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">03172</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">int</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Octal (base-8) integer. Begins with 0 (zero).<br />Decimal equivalent is 1658.</font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">0x67A</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">int</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Hexadecimal (base-16) integer. Begins with 0 (zero), then either </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">x</font><font face="Times New Roman, Times, Serif" size="2"> or </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">X</font><font face="Times New Roman, Times, Serif" size="2">. Decimal equivalent is 1658.</font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">65535U</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">unsigned聽int</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Unsigned constants end in </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">U</font><font face="Times New Roman, Times, Serif" size="2"> or </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">u</font><font face="Times New Roman, Times, Serif" size="2">.</font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">421L</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">long</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Explicit </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">long</font><font face="Times New Roman, Times, Serif" size="2"> constant. Ends in </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">L</font><font face="Times New Roman, Times, Serif" size="2"> or </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">l</font><font face="Times New Roman, Times, Serif" size="2">.</font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">53100</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">long</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Implicit </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">long</font><font face="Times New Roman, Times, Serif" size="2"> constant, assuming the machine's maximum </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">int</font><font face="Times New Roman, Times, Serif" size="2"> is, say, </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">32767</font><font face="Times New Roman, Times, Serif" size="2">.</font></td></tr><tr><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">389123487UL</font></td><td valign="top"><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">unsigned聽long</font></td><td valign="top"><font face="Times New Roman, Times, Serif" size="2">Unsigned </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">long</font><font face="Times New Roman, Times, Serif" size="2"> constants end in </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">UL</font><font face="Times New Roman, Times, Serif" size="2"> or </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">LU</font><font face="Times New Roman, Times, Serif" size="2"> in any combination of uppercase and lowercase letters.</font></td></tr></table></td></tr></table><br /></td></tr></table><p><font size="0"></font></p>聽 </td> </tr> <tr> <td align="left" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_504.html">< previous page</a></td> <td align="center" width="40%" style="background: #EEF3E2"><strong style="color: #2F4F4F; font-size: 120%;">page_505</strong></td> <td align="right" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_506.html">next page ></a></td> </tr> </table> </body> </html>⌨️ 快捷键说明
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