CODEWITHSUNDEEP
javastring
user09
user09

Reputation: 956

Better way of comparing two numberic string values

I am comparing two numeric string values like below 

String version1 = "01.00.00"
String version2 = "01.01.00"

if (version2.compareTo(version1) >= 0) { //false
}

but this is failing when I have 

    String version1 = "01.99.00"
    String version2 = "01.100.00"
    if (version2.compareTo(version1) >= 0) { //true
    }

even though "01.100.00" greater than "01.99.00" . Any better approach compare these two string and determine if version2 is greater than version1

Upvotes: 1

Views: 54

Answers (2)

RaffleBuffle
RaffleBuffle

Reputation: 5455

You need to interpret the strings as numbers and compare these. If your strings follow this pattern - strings of digits separated by periods - you could do this cheaply using something like this: 

int num1 = Integer.parseInt(version1.replace(".", ""));
int num2 = Integer.parseInt(version2.replace(".", ""));
if(num2 >= num1) {...}

Upvotes: 0

Arvind Kumar Avinash
Arvind Kumar Avinash

Reputation: 79620

You can use the following custom Comparator:

class MyComparator implements Comparator<String> {    
    @Override
    public int compare(String s1, String s2) {  

        int compVal;   

        int s1index1 = s1.indexOf(".");
        String s1part1 = s1.substring(0, s1index1);
        String s1part2 = s1.substring(s1index1 + 1, s1.lastIndexOf("."));
        String s1part3 = s1.substring(s1.lastIndexOf(".") + 1);

        int s2index1 = s2.indexOf(".");
        String s2part1 = s2.substring(0, s2index1);
        String s2part2 = s2.substring(s2index1 + 1, s2.lastIndexOf("."));
        String s2part3 = s2.substring(s2.lastIndexOf(".") + 1);

        compVal = Integer.compare(Integer.parseInt(s1part1), Integer.parseInt(s2part1));
        if (compVal == 0) {
            compVal = Integer.compare(Integer.parseInt(s1part2), Integer.parseInt(s2part2));
            if (compVal == 0) {
                compVal = Integer.compare(Integer.parseInt(s1part3), Integer.parseInt(s2part3));
            }
        }
        return compVal;
    }
}

Upvotes: 3

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