How to Use the PHP operator = to compare strings

The output result of the above Code is:

Bool (true). Therefore, when comparing strings, we recommend that you use the PHP operator = to strictly check strings or use functions such as strcmp, this avoids possible problems.

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. At the end of the introduction of the PHP operator =, if that sentence is annoying, it will strictly check and filter external data.