Php：while...endwhile 有什么区别；而 { // 这里的东西 }
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Php: what's the difference between while...endwhile; and while { // stuff here }
提问by redconservatory
What's the difference between
有什么区别
while (expression):
// do stuff
endwhile;
and
和
while {
}
回答by Jeff Davis
There is no functional difference.
没有功能差异。
In practical use I find that:
在实际使用中，我发现：
while (expression):
// do stuff
endwhile;
Is more readable for the designers when you are embedding php code within html. IE:
当您在 html 中嵌入 php 代码时，对设计人员来说更具可读性。IE：
<? while ($cssClass = array_pop($array)): ?>
<li class="<?=$cssClass?>">
<? endwhile; ?>
Whereas:
然而：
while {
}
Is more readable within a php code block.
在 php 代码块中更具可读性。
回答by S M
There's no difference, it comes down to personal preference.
没什么区别，看个人喜好。
回答by Jon
There's no real difference when writing code.
编写代码时没有真正的区别。
There can be a difference in levels of convenience in very special circumstances. For example, suppose you are writing a template engine that converts template code to native PHP code which is then cached and executed directly for speed.
在非常特殊的情况下，便利程度可能会有所不同。例如，假设您正在编写一个模板引擎，它将模板代码转换为原生 PHP 代码，然后缓存并直接执行以提高速度。
In this case, the fact that while...endwhile;avoids using braces may allow you to simplify your parsing algorithm if e.g. it recognizes variables that should be substituted with a syntax like {$var}, which also uses braces.
在这种情况下，如果while...endwhile;避免使用大括号的事实可能允许您简化解析算法，例如，如果它识别应该用类似语法替换的变量{$var}，它也使用大括号。
Of course this is a pretty small benefit in a really extraordinary situation, but you take what you can. :)
当然，在非常特殊的情况下，这只是一个很小的好处，但你可以尽你所能。:)
回答by Brandon Lee
The difference is negligible when the code is actually run, but when coding I find that typing the brackets is (1): quicker, (2): more conventional, and (3): allows for less chance of error (endwhle anyone?).
当代码实际运行时，差异可以忽略不计，但在编码时我发现输入括号是（1）：更快，（2）：更传统，以及（3）：允许更少的错误机会（结束任何人？） .
As a bonus, the editor I use auto-formats the while loops (with brackets, by default) and down the road, if anything is off, the built-in bracket-matching function will catch it.
作为奖励，我使用的编辑器会自动格式化 while 循环（默认情况下带括号），然后，如果有任何关闭，内置的括号匹配功能将捕获它。
