为什么在每个语句的a中重命名变量？

Question

I have wondered for a while now, what the reason is behind the renaming of a variable for a foreach statement. So for example, why is this:

foreach ($Foobar as $Foo) {};

Not used like this:

foreach ($Foobar) {};

I understand that this would just check to see if the value was true and is therefore a bad example, yet that doesn't explain why the whole variable needs to be renamed?

Answer 1

because you don't rename the variable, you declare another variable where the foreach result on every loop is stored in.

as a example you have this array

array('key' => 'value', 'foo' => 'bar');

and use this foreach syntax

foreach ($Foobar as $value)

the variable $value hold the value from the current loop of the array.

output each loop

• first loop => $value holds value
• second loop => $value holds bar

or your can write it like this

foreach ($Foobar as $key =>  $value)

with this on each loop the array key and value are written in $key and $value

output each loop

• first loop => $value holds value / $key hold key
• second loop => $value holds bar / $key hold foo