blocks|key|244429|text|请始终使用牙套：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|244430|if(boolean)
++++oneliner();
nextLineOfCode();|code-block|syntax|javascript|244431|与以下情况不同：|244432|if(boolean)
{
++++oneliner();
}
nextLineOfCode();|244433|如果oneliner()是一个#定义的函数，并且没有定义它，那么您的下一行代码就会突然受到if()的约束。同样的情况也适用于for循环等。使用大括号，那么下一段代码从不会无意中以if/for等为条件。|244434|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Always use braces:

<pre><code>if(boolean)
 oneliner();
nextLineOfCode();
</code></pre>

is not the same as:

<pre><code>if(boolean)
{
 oneliner();
}
nextLineOfCode();
</code></pre>

If oneliner() is a #defined function, and it isn't defined then your next line of code suddenly becomes subject to the if(). Same thing applies to for loops etc. With braces then the next piece of code never unintentionally becomes conditional on the if/for etc.

blocks|key|366966|text|我使用的前3种防御性编码实践如下|type|unstyled|depth|inlineStyleRanges|entityRanges|data|366967|366968|单元测试|ordered-list-item|366969|366970|366971|366972|对于代码的质量，没有比支持您的好的单元测试更好的防御方法了。|366973|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|N|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|O|8|@]|9|@]|A|$]]|$1|F|3|D|5|E|7|P|8|@]|9|@]|A|$]]|$1|G|3|D|5|E|7|Q|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|R|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|S|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|L|$]]

The top 3 defensive coding practices I employ are

<ol>
<li>unit testing</li>
<li>unit testing</li>
<li>unit testing</li>
</ol>

There is no better defense for the quality of your code than a good unit test to back you up.

blocks|key|244399|text|这是一个简单而明显的问题，但我从来没有在代码中重复过两次相同的字符串常量，因为我知道如果我重复了，我就会拼写错误之一:)使用常量，伙计！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|244400|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

This is a simple and obvious one, but I NEVER EVER NEVER repeat the same string constant twice in my code, cause I KNOW that if I do I will be spelling one of them wrong :) Use constants, people!

blocks|key|244513|text|将字符串与常量进行比较时，请写入|type|unstyled|depth|inlineStyleRanges|entityRanges|data|244514|if+("blah".equals(value)){}|code-block|syntax|javascript|244515|而不是|244516|if+(value.equals("blah")){}|244517|以防止NullPointerException。但这是我唯一一次使用建议的编码风格(原因是"if+(a+=1).“在Java中是不可能的)。|244518|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

When comparing a string with a constant, write

<pre><code>if ("blah".equals(value)){}
</code></pre>

instead of 

<pre><code>if (value.equals("blah")){}
</code></pre>

to prevent a NullPointerException. But this is the only time I use the suggested coding-style (cause "if (a = 1)..." is not possible in Java).

blocks|key|244550|text|当我在Javascript世界中时，我总是试图记住的一件事是始终在返回关键字的同一行上启动函数的返回值。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|244551|function+one(){
++++return+{
++++++++result:"result"
++++};
}

function+two(){
++++return+
++++{
++++++++result:"result"
++++};
}|code-block|syntax|javascript|244552|这两个函数将不会返回相同的值。第一个函数将返回一个属性结果设置为“结果”的对象。第二个函数将返回undefined。这是一个非常简单的错误，它的发生是因为Javascript过于狂热的半结肠插入策略。分号在Javascript中是半可选的，因此Javascript引擎将在它认为应该在的地方添加半coons。因为return实际上是一个有效的语句，所以返回语句之后将插入分号，而函数的其余部分将基本上被忽略。|offset|length|style|CODE|244553|entityMap^0|0|0|1C|9|4C|6|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

One of the things I always try to remember when I am in the Javascript world is to always start the return value of a function on the same line as the return key word.

<pre><code>function one(){
 return {
 result:"result"
 };
}

function two(){
 return 
 {
 result:"result"
 };
}
</code></pre>

These 2 functions will not return the same value. The first function will return an Object with a property results set to "result". The second function will return <code>undefined</code>. It's a really simple mistake and it happens because of Javascript's over-zealous Semi-Colon Insertion strategy. Semi-colons are semi-optional in Javascript and because of this the Javascript engine will add semi-coons where it thinks it's should be. Because <code>return</code> is actually a valid statement a semi-colon will be inserted after the return statement and the rest of the function will essentially be ignored.

blocks|key|244589|text|在我的博客里：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|244590|244591|认为积极，并提前返回加上避免深嵌套。而不是|ordered-list-item|244592|244593|如果(值!=空){.做一些有价值的事情.}回报|244594|写|244595|如果(值为==+null)+{返回}.使用值.|244596|避免“字符串常量”(即多处引号中的相同文本)。始终定义一个真正的常量(有一个名称和一个可选的注释，说明它的含义)并使用它。|unordered-list-item|244597|244598|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|T|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|U|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|V|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|O|7|Z|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|R|$]]

From my blog:

<ol>
<li>Think positive and return early plus avoid deep nesting. Instead of

if (value != null) {
 ... do something with value ...
}
return

write

if (value == null) {
 return
}
... do something with value ...</li>
<li>Avoid "string constants" (i.e. the same text in quotes in more than one place). Always define a real constant (with a name and an optional comment what it means) and use that.</li>
</ol>

blocks|key|367032|text|mutable)|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|367033|Avoid+|unordered-list-item|367034|
|367035|总是在我可以使用的任何地方初始化变量|367036|367037|+use+const+(不使用裸内存动态分配或其他resources|367038|Always使用大括号|367039|代码用例--在尽可能多的有用警告(至少-Wall+-Wextra+-ansi+-pedantic+-Werror)|367040|H+116使用最简单的工具(在我当前的环境中，即D17+->+D18+->+C%2B%2B)中)。H+219F+220|367041|367042|entityMap^0|0|7|0|0|0|0|0|5|5|0|0|J|11|0|0|5|O|7|19|A|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|11|8|@]|D|@]|E|$]]|$1|I|3|J|5|6|7|12|8|@]|D|@]|E|$]]|$1|K|3|L|5|H|7|13|8|@]|D|@]|E|$]]|$1|M|3|J|5|6|7|14|8|@]|D|@]|E|$]]|$1|N|3|O|5|H|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|P|3|Q|5|H|7|18|8|@]|D|@]|E|$]]|$1|R|3|S|5|H|7|19|8|@$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|T|3|U|5|6|7|1C|8|@$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@]|E|$]]|$1|V|3|-4|5|6|7|1J|8|@]|D|@]|E|$]]|$1|W|3|-4|5|6|7|1K|8|@]|D|@]|E|$]]]|X|$]]

<ul>
<li>Always initialize variables</li>
<li>Use <code>const</code> wherever I can (without using <code>mutable</code>)</li>
<li>Avoid bare dynamic allocation of memory or other resources</li>
<li>Always use curly braces</li>
<li>Code use-cases and tests for any class before coding implementation</li>
<li>Turn on as many useful warnings as I can (<code>-Wall -Wextra -ansi -pedantic -Werror</code> at a minimum)</li>
<li>Use the simplest tool that solves the problem (in my current environment, that's <code>bash</code> -> <code>grep</code> -> awk -> Python -> C++).</li>
</ul>

blocks|key|246003|text|就我个人而言，我不喜欢这种防御性的风格，它使代码难以阅读。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|246004|VC编译器警告级别4将发现此错误(可能)。|246005|“警告C4706:条件表达式中的赋值”|246006|您可以在任何级别上只启用此特定编译器警告：|246007|#pragma+warning(3,4706)|code-block|syntax|javascript|246008|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|R|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|S|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Personally, I dislike this defensive style, it makes the code hard ro read.

VC compiler warning level 4 will spot this (possible) error. 
"warning C4706: assignment within conditional expression"

You can enable just this specific compiler warning, at any level: 

<pre><code>#pragma warning(3,4706)
</code></pre>

blocks|key|366944|text|我不再使用你能做的语言|type|unstyled|depth|inlineStyleRanges|entityRanges|data|366945|if+a+=+5:+print+a|code-block|syntax|javascript|366946|这使我省去了无数的头痛。|366947|更严肃的是..。现在，我总是在编写ifs和for循环之后立即编写大括号，然后再填充它们。这确保了我的括号总是对齐的。|offset|length|style|CODE|366948|entityMap^0|0|0|0|H|2|L|3|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|T|8|@$K|U|L|V|M|N]|$K|W|L|X|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

I stopped using languages where you can do

<pre><code>if a = 5: print a
</code></pre>

This has saved me tons of headaches =). 

On a more serious note... I now always write the curly braces right after I write my <code>if</code>s and <code>for</code> loops, and then fill them in afterwards. This makes sure my brackets are always aligned.

blocks|key|245925|text|返回可变对象的副本，即数组的副本，而不是可变对象本身。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|245926|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Returning a copy of a mutable object, i.e. a copy of an array, not the mutable object itself.

blocks|key|366975|text|避免不必要的测试。示例|type|unstyled|depth|inlineStyleRanges|entityRanges|data|366976|366977|if(bool+==+true)|ordered-list-item|366978|指针检查if(指针)|366979|366980|编辑:如果(指针)不可读，所以现在我更喜欢if(NULL+!=指针)|366981|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|N|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|E|7|P|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|L|$]]

Avoid unnecessary test.
Example 

<ol>
<li>if(bool == true)</li>
<li>Pointer checks if(pointer)</li>
</ol>

EDIT:
if(pointer) is not readable so nowadays I prefer if(NULL != pointer)

blocks|key|366993|text|几件事：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|366994|366995|是的，1行块.用牙套..。糟糕的是，大多数优秀的IDE都会为你编写代码。|unordered-list-item|366996|会在您编写代码后对它进行注释，或者如果您提前编写代码，请重新阅读您的评论。确保您的代码仍然按照注释的要求执行。|366997|单元测试是重新读取代码的一个很好的后盾。|366998|总是记录异常.或者，在没有这样说的情况下，永远不要捕获异常，至少在调试.|366999|中是如此。|367000|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|R|8|@]|9|@]|A|$]]|$1|F|3|G|5|E|7|S|8|@]|9|@]|A|$]]|$1|H|3|I|5|E|7|T|8|@]|9|@]|A|$]]|$1|J|3|K|5|E|7|U|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|V|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|O|$]]

Couple things:

<ul>
<li>Yes, the 1-line blocks. Use the braces... heck, most good IDE's will make em for you.</li>
<li>Comment your code after you write it, or re-read your comments if you did it ahead of time. Make sure your code still does what the comments say.</li>
<li>Unit testing is a great fallback to re-reading your code.</li>
<li>Always log an exception... or, NEVER catch an exception without saying so, at least in debug.</li>
</ul>

blocks|key|244607|text|)那么，如果我做错了什么，就不需要编写"5+==+a“来得到警告了:)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|244608|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Installed Resharper ;)
Then I don't need to write "5 == a" to get warned if I did something wrong :)

Ever since I first wrote

<pre><code>if ($a = 5) {
 # do something with $a, e.g.
 print "$a";
}
</code></pre>

and went through the normal puzzling session of 

<ul>
<li>why is the result always true</li>
<li>why is $a always 5</li>
</ul>

until I realized, I'd assigned 5 to $a, instead of performing a comparison.

So I decided to write that kind of condition above as 

<pre><code> if (5 == $a)
</code></pre>

in other words: 

always place the constant value to the left side of the comparison operator, resulting in a compilation error, should you forget to add the second "=" sign.

I tend to call this defensive coding and tend to believe it's a cousin to defensive-programming, not on the algorithmic scale, but keyword by keyword. 

What defensive coding practices have you developed? 

<hr>

One Week Later: 

A big "thank you" to all who answered or might add another answer in the future. 

Unfortunately (or rather fortunately!) there is no single correct answer. For that my question was to broad, asking more for opinions or learnings of experience, rather than facts.

defensive coding practices

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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自从我第一次写if ($a = 5) {   #  do something with $a, e.g.   print "$a";}并经历了正常的困惑期为什么结果总是真为什么$a总是5直到我意识到，我给$a分配了5，而不是执行比较。所以我决定把上面的条件写成 if (5 == $a)换言之：如果您忘记添加第二个"=“符号，总是将常量值放在比较运算符的左侧，从而导致编译错误。我倾向于称之为防御性编

问防御编码实践
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