在 Groovy 语言中如何根据字符串中的值和位置替换字符串中的字符

Question

I am looking to amend the values of a string IF certain positions within a string are certain values for example I have a postcode L65 OBH and I need to do the following:

(1)

If the 1st value in the first section of the string (split by white space) = L it needs to be changed to T. This would then give:

T65 OBH

(2)

Then if the 2nd value in the first section of the string (split by white space) = 6 it needs to be changed to 7. This would then give:

T75 OBH

(3)

Then if the 1st value in the second section of the string (split by white space) = O it needs to be changed to 2. This would then give:

T75 2BH

(4)

Then if the 3rd value in the second section of the string (split by white space) = H it needs to be changed to P. This would then give:

T75 2BP

I'm assuming that I need to use replaceall and a number of IF statements but I am struggling to work this out, particularly how to split the 2 different parts of the postcode out treat them as separate enteties....can anyone help please

Answer 1

I'd write a helper method for the replacement rules:

def postcode = 'L65 0BH'

def (first, second) = postcode.split(/\s+/)

def replaceIf(String token, int position, String match, String replacement) {
    (0..<token.length()).collect { index ->
        if(index == position && token[index] == match) {
            replacement
        }
        else {
            token[index]
        }
    }.join()
}

first = replaceIf(first, 0, 'L', 'T')
first = replaceIf(first, 1, '6', '7')
second = replaceIf(second, 0, '0', '2')
second = replaceIf(second, 2, 'H', 'P')

assert "$first $second" == 'T75 2BP'

Answer 2

def strVal= "L65 OBH"
strVal.replaceFirst(/^L/, "T")

def strVal1= "L65 OBH"
strVal1.replaceFirst(/^6/, "7")

and so on using the same replaceFirst() method