min()
-- Find lowest value
Syntax : mixed min ( number arg1, number arg2 [, number ...])

Syntax : mixed min ( array numbers [, array ...])
min() returns the numerically lowest of the parameter values.
If the first and only parameter is an array, min() returns the lowest value in that array. If the first parameter is an integer, string or float, you need at least two parameters and min() returns the smallest of these values. You can compare an unlimited number of values.

Note: PHP will evaluate a non-numeric string as 0, but still return the string if it's seen as the numerically lowest value. If multiple arguments evaluate to 0, min() will use the first one it sees (the leftmost value).