javascript - Some problems with ternary operator

Question

Answer 1

See inside the black box, the value of la here is 0. In the sentence you marked, la == 0 ? 1 : la - 1, the output value is indeed 1 (because la == 0 established), but there is no place in this line to assign a value to la, so the value of la will not change and is still 0.

Answer 2

la == 0 ? la = 1 : la - 1

Answer 3

la==0?1:la-1

This statement does nothing at all and needs to be changed to;

la=la==0?1:la-1