The challenge
Complete the solution so that it reverses all of the words within the string passed in.
Example:
1
2
|
ReverseWords.reverseWords("The greatest victory is that which requires no battle");
// should return "battle no requires which that is victory greatest The"
|
The solution in Java code
Option 1 (using StringBuilder):
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
public class ReverseWords{
public static String reverseWords(String str){
String[] words = str.split(" ");
StringBuilder sb = new StringBuilder();
for (int i=words.length-1; i>=0; i--) {
sb.append(words[i]).append(" ");
}
return sb.toString().trim();
}
}
|
Option 2 (using Arrays):
1
2
3
4
5
6
7
8
9
10
11
|
import java.util.*;
public class ReverseWords{
public static String reverseWords(String str){
List Words = Arrays.asList(str.split(" "));
Collections.reverse(Words);
return String.join(" ", Words);
}
}
|
Option 3 (using streams):
1
2
3
4
5
6
7
8
9
|
import java.util.Arrays;
public class ReverseWords{
public static String reverseWords(String str){
return Arrays.stream(str.split(" ")).reduce((x, y) -> y+" "+x).get();
}
}
|
Test cases to validate our solution
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
import org.junit.Test;
import static org.junit.Assert.assertEquals;
import org.junit.runners.JUnit4;
public class SolutionTest {
@Test
public void testSomething() {
assertEquals("eating like I", ReverseWords.reverseWords("I like eating"));
assertEquals("flying like I", ReverseWords.reverseWords("I like flying"));
assertEquals("nice is world The", ReverseWords.reverseWords("The world is nice"));
assertEquals("nice so not is world The", ReverseWords.reverseWords("The world is not so nice"));
assertEquals("beatiful is Life", ReverseWords.reverseWords("Life is beatiful"));
assertEquals("won! we hello Hello", ReverseWords.reverseWords("Hello hello we won!"));
}
}
|
