Do you know the difference between the output of php var_export and var_dump?

var_export must return legal php code, that is to say, the code returned by var_export can be directly assigned to a variable as a php code. And this variable will get the same type of value as var_export

Problem discovery
When tracking yratings_get_targets,
error_log (var_export(yblog_mspconfiginit("ratings"),true)); always prints out that the return value of yblog_mspconfiginit("ratings") is NULL

, which leads me to think that the connection to the DB cannot be established, which is wrong. Been on the road for a day.
Finally I discovered that this is one of the differences between var_export and var_dump

This is:
Cause of the problem
var_export must return legal PHP code, that is to say, the code returned by var_export can be directly assigned to a variable as PHP code. And this variable will get the same type of value as var_export

However, when the variable type is resource, it cannot be simply copycopied, so , When the variable of var_export is of resource type, var_export will return NULL

Instance

$res = yblog_mspconfiginit("ratings");
var_dump($res);
var_export($res);结果:
resource(1) of type (yahoo_yblog)
NULL再比如:
$res = fopen('status.html', 'r');
var_dump($res);
var_export($res);结果:
resource(2) of type (stream)
NULL

The above is the detailed content of Do you know the difference between the output of php var_export and var_dump?. For more information, please follow other related articles on the PHP Chinese website!