Use the = Operator in PHP to compare strings

A new article recently published on Greg Beaver's blog about comparing strings in PHP with the = operator mentions the = operator of PHP when comparing strings..

In some cases, PHP converts a numeric data (such as a string containing digits) to a numeric value. The = Operator is one of them. When the = Operator is used to loosely compare two strings, PHP converts the string of the class value to a numerical value for comparison. The following experiment confirms this conclusion:

<?php
var_dump('01' == 1);
?>

The output result of the above Code is:
Bool (true)

Therefore, when comparing strings, we recommend that you use the = Operator to strictly check strings or use functions such as strcmp () to avoid possible problems. The PHP type comparison table in the PHP Manual also describes this in detail.

In addition, common in_array () functions also have weak types. See the following code:

<?php
var_dump(in_array('01', array('1')));
?>

The output result of the above Code is:
Bool (true)

I believe that PHP programmers who have used this function for security checks all know what security issues will occur? Fortunately, the in_array () function provides us with the third parameter. Setting it to true enables the forced type check mechanism of the in_array () function, as shown in the following code:

<?php
var_dump(in_array('01', array('1'), true));
?>

Output result:
Bool (false)

Since PHP is a weak language, the concept of data type is weakened in PHP. Therefore, if the data type is excessively neglected during programming (which is also a common problem for most PHP programmers), some problems may occur and even cause security vulnerabilities. Finally, if that sentence is annoying, it will strictly check and filter external data.