Reverse a string pattern in java

Question

I have this input String input = "TOM DICK HARRY";, I want output as "HARRY DICK TOM"

I have tried this (which I think is not an optimal way of doing)

public static void main(String[] args) {
    String input = "TOM DICK HARRY";

    String inputArr [] = input.split(" ");

    for (int i = inputArr.length; i >0; i--) {
        System.out.print(inputArr[i-1]+" ");    
    }

}

Is there any built in method to do this?

Unless you're doing this for an incredibly long string, what you have here is probably a good enough way of doing this. — Ownaginatious, Sep 20 '15 at 07:31
What you have is fine. Why do you think it's not? In what way isn't it "optimum"? — JB Nizet, Sep 20 '15 at 07:53
One can also use `ArrayUtils.reverse(inputArr); System.out.println(Arrays.toString(inputArr));` but then it would print square brackets in console like this: `[HARRY, DICK, TOM]`. So I found one more way not doing it optimum way. — paul, Sep 20 '15 at 07:58

score 0 · Answer 1 · answered Sep 20 '15 at 08:24

0

Using Guava you can do:

Joiner.on(' ').join(Lists.reverse(Splitter.on(' ').splitToList("TOM DICK HARRY")));

answered Sep 20 '15 at 08:24

Dzieciak

83
11

score 0 · Accepted Answer · answered Sep 20 '15 at 08:42

Using only vanilla Java 8:

public static void main(String[] args) {
    String input = "TOM DICK HARRY";

    List<String> list = Arrays.asList(input.split(" "));
    Collections.reverse(list);
    System.out.println(list.stream().collect(Collectors.joining(" ")));
}

It isn't necessarily "better" than your solution, but it uses standard API, which is what you seem to be after.

Reverse a string pattern in java

2 Answers2