如何找到两个符文之间的距离

Question

I'm trying to solve a couple of example programming problems to familiarize myself with the language.

I am iterating over a string as follows:

func main() {
    fullFile := "abcdDefF"

    for i := 1; i < len(fullFile); i++ {
        println(fullFile[i-1], fullFile[i], fullFile[i-1]-fullFile[i])
    }
}

In the loop I want to get the difference between the current rune and the previous rune (trying to identify lower-case - upper-case pairs by finding any pairs where the difference is == 32.

Strangely, the subtraction doesn't work properly (in fact seems to yield addition in cases where I would expect a negative number) although I would expect it to since runes are represented by int32.

Answer 1

Figured it out: the data type returned was a byte.

Explicitly converted to int and everything works as expected.

func main() {
    fullFile, _ := ioutil.ReadFile("input/input.txt")
    previous := 0
    current := 0
    for i := 1; i < len(fullFile); i++ {
        previous = int(fullFile[i-1])
        current = int(fullFile[i])
        println(current, previous, current-previous)
    }
}