Top 3 builtin-functions open source projects

Mock built-in PHP functions (e.g. time()) with Prophecy (phpspec).

Mock non deterministic built-in PHP functions (e.g. time() or rand()) with Mockery.

The function is a block of code defined with a name. We use functions whenever we need to perform the same task multiple times without writing the same code again. It can take arguments and returns the value.