将“未定义”索引映射到数组

Question

Let's say we have an Array like so:

var example = ["a", "b", "c", "d", "e"]

We know that we can access an index of 0-4:

example[0] == "a"
example[1] == "b"
example[2] == "c"
example[3] == "d"
example[4] == "e"

However, we also want to map an undefined index. For example:

example[0] == example[5] == example[10] == example[15] == example[20] == "a"
example[1] == example[6] == example[11] == example[16] == example[21] == "b"
example[2] == example[7] == example[12] == example[17] == example[22] == "c"
example[3] == example[8] == example[13] == example[18] == example[23] == "d"
example[4] == example[9] == example[14] == example[19] == example[24] == "e"

Though it may be simple, the math is simply escaping my mind. Keep in mind the example.length is not fixed and may be different at times. How would one go about this?

Answer 1

您似乎想使用模数 ：

example[i%example.length]