1、Tuples are compared from left to right, one value at a time, until the comparison finds two values that aren’t equal.
(1, "zebra") < (2, "apple")
You can compare two tuples if they have the same type and the same number of values. Tuples are compared from left to right, one value at a time, until the comparison finds two values that aren’t equal.
2、nil-coalescing operator (a ?? b)
