#1
See, the output here is ‘‘e’’, but why? it says u have to count from 0, so in this case it should be ‘‘v’’…hm
#1
The length of an empty string (""
) is 0
. Length is the number of characters in the string (or items in the array).
const str = 'abcde';
str[0]; // a
str[1]; // b
str[2]; // c
str[3]; // d
str[4]; // e
str.length; // 5
str[str.length - 1]; // e
str[str.length - 2]; // d
str[str.length - 3]; // c
str[str.length - 4]; // b
str[str.length - 5]; // a
The math all adds up.
See fencepost error for an explanation if you’re still confused. You can think of array/string indexes as fence panels and array/string lengths as the ending fence posts.