The above is very professional, and it doesn't matter how the landlord is. The landlord must be a novice, using easy-to-understand terms.

First of all, does the landlord know the data type of php language? If not, you can check the basic books.

Here are two data types. One is int (integer): the number as the saying goes. One is a string, as the saying goes, the text format. The former is plastic, and the latter is string because of quotation marks. The data types are different.

= = This comparison symbol is just a general comparison, that is, 0 = = "0" will be judged as true.

= = = This symbol is a strict judging symbol, which not only judges whether the numbers are the same, but also judges whether they belong to the same data type. Obviously, the data types of the two are different, so they are false.