为什么计数不如$ count [英] Why count is bad than $count

问题描述

我只是回顾不同问题的答案，以了解更多。我看到一个答案，它表示在php中写作是不好的习惯

$ b $ （$ i = 0; $ i



<它说在循环中调用count函数会降低代码的速度。关于这个问题的意见的讨论并不清楚。我想知道为什么这不是好的做法。你应该这样做：

解决方案

b $ b

  $ count = count（$ array）; （$ i = 0; $ i <$ count; $ i ++）... 
  

<这样做的原因是因为如果你在for循环中放置 count（$ array），那么每次迭代都要调用count函数，这会减慢速度。

但是，如果将计数放入一个变量中，则这是一个静态数字，不必每次重新计算。

I was just reviewing the answers to different questions to learn more. I saw an answer which says that it is bad practice in php to write

for($i=0;$i<count($array);$i++)

It says that calling the count function in the loop reduces the speed of the code. The discussion in the comments on this question was not clear. I want to know why it is not good practice. What should be the alternative way of doing this?

解决方案

You should do this instead:

$count = count($array);
for($i=0;$i<$count;$i++)...

The reason for doing this is because if you put the count($array) inside the for loop then the count function would have to be called for every iteration which slows down speed.

However, if you put the count into a variable, it is a static number that won't have to be recalculated every time.

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