Upgrade PHP7 to avoid pitfalls

Recommendation (free):PHP7

I heard that this version of php7 has been greatly improved before, and finally The company's projects will also be upgraded to PHP7.

Before upgrading, I read some introductions compiled by everyone and found that this version has great changes from the bottom up. Of course, the efficiency has also been improved a lot.

Except for some new features (everyone has already written this completely, I will write some that I haven’t seen, and I will update it slowly as the project progresses)

Extension part

1. Pay attention to your php version and download/install the corresponding extension. I am in a windows environment, so I download the dll file to use it

Friendly reminder : Pay attention to the extension address of the ini configuration. I was surprised at first, why none of my extensions were extended, and there was no information in phpinfo()!_{I never expected that the address was written wrong!}~~It’s time to fight

There should be more people using memcache in the 2.5. After some research, there were some that switched to memcached, and some that were recompiled by myself. I thought that since we upgraded relatively late, someone should have uploaded this version that supports PHP7, so I found it.

Post the link and go directly to the corresponding version: https://github.com/nono303/PHP7-memcache-dll

3.phalcon also has a version that supports php7. You can also directly find the corresponding version: https://github.com/phalcon/cphalcon/releases/tag/v3.4.1

Code part

1. The split method can no longer be used in PHP. You can usepreg_splitorstr_splitorexplodeaccording to your needs.

2. Custom function When passing parameters, what does it mean that the parameters must not have no value? See the following code description

Error:

function test($name) { if(empty($name)) { echo 'php7时会出现致命错误！~'根本到不了这里; } }

Correct:

function test($name=null) { if(empty($name)) { echo '这里就可以正常执行了~'; } }

Unfortunately, many of my projects have This is how it is written (roughly reading a default time when there is no time value!~)

Indirect use of changes in variables, properties and methods

##Foo::$bar'baz ' Foo::{$bar['baz']}() (Foo::$bar)['baz']()

Expression	Parsing method in PHP 5	Parsing method in PHP 7
$$foo['bar'] ['baz']	${$foo['bar']['baz']}	($$foo)['bar']['baz']
$$foo['bar']['baz']	$foo->{$bar['baz']}	($ $foo)['bar']['baz']
$$foo['bar']['baz']	$foo->{ $bar['baz']}()	($$foo)['bar']['baz']

Code that uses the old right-to-left parsing order must be rewritten to explicitly use parentheses to indicate the order (see the table above). This allows the code to maintain forward compatibility with PHP 7.x and backward compatibility with PHP 5.x. (Said in the document)

The other thing is that there are many more warnings when comparing 7. ##

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