The php Function sodium_crypto_pwhash_str_needs_rehash

The php function sodium_crypto_pwhash_str_needs_rehash is used to check whether or not an already-hashed password needs a rehash. It takes the current password hash and a boolean value (which is a flag to determine whether or not to rehash). Then it compares that hash to the provided plain-text password to see if the two match. If the hash and password match, the boolean is set to false, indicating that no rehash is needed.

Functions in php are a great way to write code that can be reused multiple times within a script. They allow you to do complex operations with only a small amount of code. Typically, they are defined with the keyword function followed by the name of the function, and then a list of parameters. When you call a function, you use it just like you would any other variable in your script. It is important to note that a function must be called inside parentheses or else it will not work.

A common mistake is to confuse functions with constants. You can tell a function from a constant by looking at the parentheses around it. A function always requires them, whereas constants do not.

Another important aspect of functions is their scope. A variable can be declared with a local, global, or private scope. Each of these has its own benefits and drawbacks. For example, if you declare a variable with the global keyword, it can be accessed from any function in the script. This is important because it allows you to share data between multiple parts of your code. A variable with a local scope, on the other hand, can only be accessed from within the function in which it was declared.