If you’ve been paying attention so far, you might have picked up a theme in programming—shortcuts. Defining our own functions gives us an easier way to repeat similar code throughout a program. B…

PHP includes useful built-in functions for getting information about variables. The […] function takes a variable as its argument and retur…

We can find PHP built-in functions to accomplish common tasks. Need to reverse a string? There’s a built-in function for that! The [ […] function](https://www.php.net/manual/en/function.strrev…

A substring is a portion of a string. For example, […] is a substring of the string […] and […] is a substring of the string […] . Manipulating strings is very common in programmin…

Another common task in programming is working with numbers, so it shouldn’t surprise us that PHP comes with some handy built-in functions for working with numbers. The [ […] function](https://…

Generating random numbers may not seem obviously useful, but, as your programs become increasingly complicated, you’ll see this is actually a common task—for example to randomize data for testing. …

In order to understand built-in functions we’ve never used before, we’ll want to get comfortable understanding how they are represented in the documentation. Documentation typically includes: + The…

In order to find out about built-in functions (and other language features), you’ll want to get comfortable exploring the PHP documentation. The docs ca…

In this lesson, you learned that built-in functions are functions provided by PHP. You learned about several specific built-in functions, how to understand a function’s description in the documenta…