Note: this information is not available in the official docs, I found it by browsing through the source of laravel which I highly recomend for a better understanding of the framework.
The class is under laravel folder / helpers.php. I will not list all functions, only those I found very useful:
To retrieve a language line:
To dump a value and exit:
To remove an array item with “dot” notation:
Convert an Eloquent model to JSON object:
Get the file size of a file in a human readable form (Bytes, KiB etc):
And many more, feel free to explore, the library and the whole framework is very well commented.