blocks|key|2582929|text|有一个名为limits.h的文件(至少在Linux上是这样的)，它包含这种定义，例如|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2582930|/*+Maximum+value+an+`unsigned+short+int'+can+hold.++(Minimum+is+0.)++*/
#++define+USHRT_MAX+65535

/*+Minimum+and+maximum+values+a+`signed+int'+can+hold.++*/
#++define+INT_MIN+++(-INT_MAX+-+1)
#++define+INT_MAX+++2147483647

/*+Maximum+value+an+`unsigned+int'+can+hold.++(Minimum+is+0.)++*/
#++define+UINT_MAX++4294967295U|code-block|syntax|javascript|2582931|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>There is a file called limits.h (at least on Linux  there is), which holds this kind of definition e.g. </p>

<pre><code>/* Maximum value an `unsigned short int' can hold.  (Minimum is 0.)  */
#  define USHRT_MAX 65535

/* Minimum and maximum values a `signed int' can hold.  */
#  define INT_MIN   (-INT_MAX - 1)
#  define INT_MAX   2147483647

/* Maximum value an `unsigned int' can hold.  (Minimum is 0.)  */
#  define UINT_MAX  4294967295U
</code></pre>


blocks|key|851477|text|通常这是由1.0/0.0完成的，但您可能会收到编译警告。我不知道在C89中有其他可移植的方法，但是C99在math.h中有宏FP_INFINITE。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|851478|编辑:显然山姆实际上并不想要无穷大，而是整数限制，这可以在limits.h中找到，就像其他人所说的那样。|851479|entityMap^0|5|7|1H|6|1Q|B|0|T|8|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

<p>Normally this is done by <code>1.0/0.0</code>, but you may get a compile warning on that. I am not aware of other portable ways of doing it in C89, but C99 has macro <code>FP_INFINITE</code> in <code>math.h</code>.</p>

<p>EDIT: Apparently Sam didn't actually want infinity, but integer limits, which can be found in <code>limits.h</code> like others have stated.</p>


blocks|key|1172837|text|#include+<limits.h>
int+x+=+INT_MAX;|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1172838|编辑:在提问者澄清之前回答了，我只是在猜测他们想要什么类型。|unstyled|1172839|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>#include &lt;limits.h&gt;
int x = INT_MAX;
</code></pre>

<p>EDIT: answered before the questioner clarified, I was just guessing what type they wanted.</p>


blocks|key|851519|text|我通常使用在limits.h+INT_MAX中找到的*_MAX宏来表示整数等。这些宏将始终正确地设置为变量类型。即使是明确大小的类型，比如uint32，在这个头文件中也会有相应的条目。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|851520|这样做的好处是，它是该类型的变量可以容纳的最大可能值。|851521|对于您在问题中要求的无符号整数，您可以使用UINT_MAX|851522|entityMap^0|6|8|F|7|R|4|0|0|L|8|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|J|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|K|$]]

<p>I generally use the *<code>_MAX</code> macros found in <code>limits.h</code>  <code>INT_MAX</code> for  integers etc.  These will always be correctly set for the variable type.  Even the explicitly sized types such as uint32 will have corresponding entries in this header file.</p>

<p>This has the virtue of being the largest possible value that a variable of that type can hold.</p>

<p>For an unsigned integer as you asked for in your question, you would use <code>UINT_MAX</code></p>


blocks|key|2583071|text|到目前为止，获取无符号整数类型的最大值的最简单方法是将(-1)强制转换为该类型。标准(§6.2.5/9)要求执行无符号数学运算时，要取比可以表示的最大值大一的数为模，因此对于任何无符号类型T，表达式((T)-1)必须是该类型中可能的最大值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2583072|entityMap^0|2M|1|2R|7|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

<p>By far the simplest method to get the largest value for an unsigned integer type is to cast (-1) to that type. The standard (§6.2.5/9) requires that unsigned math be carried out modulo a number one greater than the largest value that can be represented, so for any unsigned type <code>T</code>, the expression <code>((T)-1)</code> will necessarily be the largest value possible in that type.</p>


blocks|key|853531|text|由于这个问题上有一个C%2B%2B标签，我建议使用numeric_limits：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|853532|#include+<limits>

unsigned+x+=+std::numeric_limits<unsigned>::max();|code-block|syntax|javascript|853533|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Since there's a C++ tag on this question, I'll suggest numeric_limits:</p>

<pre><code>#include &lt;limits&gt;

unsigned x = std::numeric_limits&lt;unsigned&gt;::max();
</code></pre>


blocks|key|1173010|text|根据您的注释，您需要一个整数(尽管您说的是“无符号整数”，因此您可能需要一个整数值，而不一定是unsigned+int)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1173011|在C中，对于无符号整数类型，当转换为该类型时，值-1被保证为该类型的最大值：|1173012|size_t+size_max+=+-1;
unsigned+int+uint_max+=+-1;
unsigned+long+ulong_max+=+-1;|code-block|syntax|javascript|1173013|将值SIZE_MAX、UINT_MAX和ULONG_MAX分别赋给变量。通常，您应该包含limits.h并使用适当的宏，但了解上面的规则是很好的。此外，SIZE_MAX不在C89中，因此size_t+size_max+=+-1;可以在C89和C99中工作。|1173014|请注意，只有无符号整数类型才能保证溢出行为。|1173015|entityMap^0|1B|C|0|O|2|0|0|2|8|B|8|K|9|18|8|24|8|2L|L|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|O|3|P|5|6|7|1C|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|R|$]]

<p>Based upon your comments, you want an <code>unsigned int</code> (although  you say "unsigned integer", so maybe you want an integral value, not necessarily an <code>unsigned int</code>).</p>

<p>In C, for unsigned integral type, the value <code>-1</code>, when converted to that type, is guaranteed to be largest value of that type:</p>

<pre><code>size_t size_max = -1;
unsigned int uint_max = -1;
unsigned long ulong_max = -1;
</code></pre>

<p>assign the values <code>SIZE_MAX</code>, <code>UINT_MAX</code> and <code>ULONG_MAX</code> to the variables respectively.  In general, you should include <code>limits.h</code> and use the appropriate macro, but it is nice to know the rule above.  Also, <code>SIZE_MAX</code> is not in C89, so <code>size_t size_max = -1;</code> will work in C89 as well as C99.</p>

<p>Note that the overflow behavior is guaranteed only for unsigned integral types.</p>


blocks|key|853597|text|另一种获取整数最大值的便携方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|853598|无符号整数|853599|unsigned+int+uMax+=+(unsigned+int)~0;|code-block|syntax|javascript|853600|有符号整数|853601|signed+int+iMax+=+(unsigned+int)~0+>>+1;|853602|解释|853603|将所有位设置为无符号整数擦除符号位，方法是将所有位向右移位一次position|853604|(unsigned+int)类型转换为无符号整数，而不是使用~0U，因为C没有缩写的后缀，字符文字(通常都小于int+)|unordered-list-item|offset|length|style|CODE|853605|853606|因此，为了获得最大的char值，只需将公式类型转换为无符号字符，依此类推。|853607|Bonus+-有符号整型的最小值|853608|只需在最大有符号整型表达式中再次反转所有位：|853609|signed+int+iMin+=+~((unsigned+int)~0+>>+1);|853610|这将第一个符号位设置为1，其余位设置为0|853611|entityMap^0|0|0|0|0|0|0|0|0|E|U|3|0|0|A|4|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1B|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1C|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|1D|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|1E|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|1F|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|1G|8|@]|9|@]|A|$]]|$1|Q|3|R|5|S|7|1H|8|@$T|1I|U|1J|V|W]|$T|1K|U|1L|V|W]]|9|@]|A|$]]|$1|X|3|-4|5|6|7|1M|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|6|7|1N|8|@$T|1O|U|1P|V|W]]|9|@]|A|$]]|$1|10|3|11|5|6|7|1Q|8|@]|9|@]|A|$]]|$1|12|3|13|5|6|7|1R|8|@]|9|@]|A|$]]|$1|14|3|15|5|F|7|1S|8|@]|9|@]|A|$G|H]]|$1|16|3|17|5|6|7|1T|8|@]|9|@]|A|$]]|$1|18|3|-4|5|6|7|1U|8|@]|9|@]|A|$]]]|19|$]]

<p>Another portable way to get maximum value of integer:</p>

<h3>Unsigned integer</h3>

<pre><code>unsigned int uMax = (unsigned int)~0;
</code></pre>

<h3>Signed integer</h3>

<pre><code>signed int iMax = (unsigned int)~0 &gt;&gt; 1;
</code></pre>

<h3>Explanation</h3>

<ul>
<li><code>~0</code> -> setting all bits to one</li>
<li><code>&gt;&gt; 1</code> -> erasing sign bit, by shifting all bits to the right by one position</li>
<li><code>(unsigned int)</code> typecasting to unsigned int after bits inversion instead of using <code>~0U</code>, because C doesn't have a suffix for short,char literals (everything smaller than int in general)</li>
</ul>

<p>So for biggest possible <code>char</code> value - just change in formula typecasting to 
unsigned char and etc.</p>

<h3>Bonus - minimum value of signed int</h3>

<p>Simply just invert all bits once more  in max signed int expression:</p>

<pre><code>signed int iMin = ~((unsigned int)~0 &gt;&gt; 1);
</code></pre>

<p>That sets first sign bit to one and the rest bits - to zero</p>


blocks|key|2583313|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2583314|首先，包含一个名为math.h|ordered-list-item|2583315|的头文件，现在，将INT_MAX等同于您要设置其最大值的整数。EXAMPLE:#include<math.h>+//the+header+file+which+need+to+be+included//+int+a=INT_MAX;+//Suppose+"a"+be+that+integer+whose+value+you+want+largest//|offset|length|style|CODE|2583316|2583317|entityMap^0|0|0|13|3U|0|0^^$0|@$1|2|3|-4|4|5|6|M|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|N|7|@]|8|@]|9|$]]|$1|D|3|E|4|C|6|O|7|@$F|P|G|Q|H|I]]|8|@]|9|$]]|$1|J|3|-4|4|5|6|R|7|@]|8|@]|9|$]]|$1|K|3|-4|4|5|6|S|7|@]|8|@]|9|$]]]|L|$]]

<ol>
<li>Firstly, include a header file named as math.h</li>
<li>Now, equate INT_MAX to the integer whose value you want to set maximum.
EXAMPLE:<code>#include&lt;math.h&gt; //the header file which need to be included//
int a=INT_MAX; //Suppose "a" be that integer whose value you want largest//
</code></li>
</ol>


<p>How would you set a variable to equal infinity (or any guaranteed largest number value) in C?</p>


How would you set a variable to the largest number possible in C?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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如何在C中将变量设置为等于无穷大(或任何有保证的最大数值)？

问如何在C中将变量设置为可能的最大数？
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问如何在C中将变量设置为可能的最大数？EN