PHP Data type judgment

There was a bit of a problem with the STBSTR () function today, because I put the results in the IF condition. When the first position is found, return 0.

In PHP, when condition = 0 is translated to false.

A simple way to wrap one layer

Is_int () Determines whether the number is not.

Isset ():                        ///variable declared empty ():                        //variable is empty defined ():///The constant has been defined define () array_key_exists (mixed key , array Search)://        Check whether the given key name or index exists in the array Is_array ()://The detection variable is an array is_numeric (mixed var):                //Detection variable is a numeric or numeric word String Is_bool ():            //Check whether the variable is Boolean is_float ():            //Detect whether the variable is floating point and is_double,is_real () are the same usage is_int ():            //Detection variable is an integer is _integer () The same usage is_string ():            //detects if the variable is a string Is_object ():            //detects if the variable is an object Is_null ():            //detection variable is NULL Whether the value is null case sensitive

The basic function is still very useful.