php null value returned from min() function

Question

Why does

var_dump(min(-100, -10, NULL, 10, 100));

return

NULL

Any references to PHP documentation would be much appreciated.

Answer 1

According to the PHP documentation on Comparison Operators , comparing NULL to anything results in both arguments being converted to bools, with NULL converting to false .

Since for numbers, only 0 or 0.0 convert to false , all of the other arguments passed to min are considered greater than NULL.