blocks|key|3234138|text|new+type需要delete|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3234139|new+type[size]需要delete+[]|3234140|用一个代替另一个是错误的。|3234141|顺便说一句，你不应该使用这样的原始指针，除非你有一个很好的理由。使用std::vector或std::array代替。|3234142|二维MxN阵列一般应该线性化成一维M*N阵列，也可以使用这些容器。|3234143|entityMap|0|LINK|mutability|MUTABLE|url|http://en.cppreference.com/w/cpp/container/vector|1|http://en.cppreference.com/w/cpp/container/array^0|0|8|A|6|0|0|E|G|9|0|0|Y|B|1A|A|Y|B|0|1A|A|1|0|2|1|4|1|H|3|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|17|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|18|8|@$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]]|D|@$9|1D|A|1E|1|1F]|$9|1G|A|1H|1|1I]]|E|$]]|$1|L|3|M|5|6|7|1J|8|@$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|1Q|8|@]|D|@]|E|$]]]|O|$P|$5|Q|R|S|E|$T|U]]|V|$5|Q|R|S|E|$T|W]]]]

<code>new type</code> requires <code>delete</code> 
<code>new type[size]</code> requires <code>delete []</code> 
Using one instead of the other is wrong.

Btw you should not use such raw pointers like this unless you have a very good reason. Use <a href="http://en.cppreference.com/w/cpp/container/vector" rel="noreferrer"><code>std::vector</code></a> or <a href="http://en.cppreference.com/w/cpp/container/array" rel="noreferrer"><code>std::array</code></a> instead.

And 2D <code>M</code>x<code>N</code> arrays should generally be linearised into 1D <code>M*N</code> arrays, also using these containers.

blocks|key|482274|text|如果你说过
int+arr5；
两者有什么区别？
删除arr；
和
删除[]+arr；|type|blockquote|depth|inlineStyleRanges|entityRanges|data|482275|其中一个有一个额外的括号。两者都可能崩溃和/或破坏堆。这是因为arr是一个局部变量，它不能是delete，d-+delete只适用于与new分配的东西。|unstyled|offset|length|style|CODE|482276|delete+[][]+arr;不是有效的语法。对于与new+int[2][2]一起分配的数组，请使用delete+[]。|482277|entityMap^0|0|V|3|1A|6|1K|6|1V|3|0|0|G|R|D|1F|9|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@$E|O|F|P|G|H]|$E|Q|F|R|G|H]|$E|S|F|T|G|H]|$E|U|F|V|G|H]]|9|@]|A|$]]|$1|I|3|J|5|D|7|W|8|@$E|X|F|Y|G|H]|$E|Z|F|10|G|H]|$E|11|F|12|G|H]]|9|@]|A|$]]|$1|K|3|-4|5|D|7|13|8|@]|9|@]|A|$]]]|L|$]]

<blockquote>
If you have said
<pre><code>int arr[5];
</code></pre>
What is the difference between
<pre><code>delete arr;
</code></pre>
and
<pre><code>delete [] arr;
</code></pre>
</blockquote>
One has an extra pair of brackets in it. Both will probably crash and/or corrupt the heap. This is because <code>arr</code> is a local variable which can't be <code>delete</code>d - <code>delete</code> only works on things allocated with <code>new</code>.
<code>delete [][] arr;</code> is not valid syntax. For an array allocated with for example <code>new int[2][2]</code>, use <code>delete []</code>.

blocks|key|1070850|text|删除的内容都不正确。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1070851|当您声明这样的数组时：|1070852|int+arr[5];|code-block|syntax|javascript|1070853|空间在stack上分配。未用delete清除堆栈上分配的内存。当堆栈在作用域退出时展开时，它会自动清理(虽然在技术上不是正确的术语)。(检查When+is+an+object+"out+of+scope"?+)|offset|length|style|CODE|1070854|如果您像这样解密数组：|1070855|int+*arr+=+new+int[5];+//+new+allocates+memory+on+heap|1070856|你打电话来|1070857|delete[]+arr;+//+this+takes+care+of+cleaning+up+memmory+on+**heap**|1070858|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/10080935/when-is-an-object-out-of-scope^0|0|0|0|3|5|1Y|X|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|15|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|16|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|17|8|@$K|18|L|19|M|N]]|9|@$K|1A|L|1B|1|1C]]|A|$]]|$1|O|3|P|5|6|7|1D|8|@]|9|@]|A|$]]|$1|Q|3|R|5|F|7|1E|8|@]|9|@]|A|$G|H]]|$1|S|3|T|5|6|7|1F|8|@]|9|@]|A|$]]|$1|U|3|V|5|F|7|1G|8|@]|9|@]|A|$G|H]]|$1|W|3|-4|5|6|7|1H|8|@]|9|@]|A|$]]]|X|$Y|$5|Z|10|11|A|$12|13]]]]

Neither of the delete's is correct.

When you declare an array like this:

<pre><code>int arr[5];
</code></pre>

The space is allocated on the <code>stack</code>. Memory allocated on the stack isn't cleaned by delete. It gets auto cleaned (Although clean is not the correct term technically) when the stack unrolls on exit of scope. (Check <a href="https://stackoverflow.com/questions/10080935/when-is-an-object-out-of-scope">When is an object &quot;out of scope&quot;?</a> )

If you declre your array like this:

<pre><code>int *arr = new int[5]; // new allocates memory on heap
</code></pre>

You call 

<pre><code>delete[] arr; // this takes care of cleaning up memmory on **heap**
</code></pre>

blocks|key|3234098|text|我想您是指new+int[5]，以及用于动态内存的相同new。否则，您将使用堆栈，而不是堆，而删除是未定义的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3234099|虽然delete+arr似乎适用于二维数组，但我认为标准要求如下：|3234100|delete+[]+arr
arr=nullptr|code-block|syntax|javascript|3234101|这是因为使用new+[]分配的内存必须用delete+[]释放，反之亦然。此外，留下悬挂的指针是危险的，因此最后一行是|3234102|entityMap^0|5|A|R|3|0|2|A|0|0|6|6|K|9|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$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]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|P|$]]

I assume you mean <code>new int[5]</code>, and the same <code>new</code> for dynamic memory. Otherwise, you are using stack, not the heap, and delete is undefined

While <code>delete arr</code> may seem to work for a 2-d array, I believe that the standard requires the following:

<pre><code>delete [] arr
arr=nullptr
</code></pre>

This is because memory allocated with <code>new []</code> must be freed with <code>delete []</code> and vice versa. Also, it is dangerous to leave dangling pointers, hence the final line

If you have said

<pre><code>int *arr = new int[5];
</code></pre>

What is the difference between 

<pre><code>delete arr;
</code></pre>

and 

<pre><code>delete [] arr;
</code></pre>

I ask this because I was trying to deallocate memory of a 2d array and

<pre><code>delete [][] arr; 
</code></pre>

did not seem to work but

<pre><code>delete arr;
</code></pre>

seemed to work fine

Thank you in advance!

Different ways to deallocate an array - 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。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

如果你说过int *arr = new int[5];两者有什么区别？delete arr;和delete [] arr;我问这个是因为我试图释放2d数组的内存delete [][] arr; 似乎没有用，但是delete arr;看上去很好提前谢谢你！

问释放数组的不同方法- c++
EN

回答 4

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问释放数组的不同方法- c++EN

回答 4

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问释放数组的不同方法- c++
EN