在java中逐字反转字符串（不使用StringBuilder）

Question

I'm having trouble getting a method to return anything. The code is supposed to take a string, reverse the string by word, and return the new string.

This is for a school assignment, and i'm trying to avoid using stringbuilder since it's not covered by the text. I'm also trying to use syntax I understand as much as possible for obvious reasons.

public static String reverseByWord(String s){
    String forward[] = s.split("\\s+");
    String backward = new String();
    for (int i=forward.length-1; i< forward.length-1; i--){
        backward += forward[i];
    }

    return backward;

Input example: "The quick brown fox" Output expected: "fox brown quick The" Output: nothing

Answer 1

for (int i=forward.length-1; i< forward.length-1; i--){
    backward += forward[i];
}

This line, int i = forward.length-1; i < forward.length-1 int i = forward.length-1; i < forward.length-1

You set i to forward.length - 1 , then you immediately tell the for loop that it should executed only if i is less than forward.length - 1

A really simple solution, just set the condition to i >= 0

Answer 2

Your for loop condition is not correct. Your logic should be from last String length to starting of string ie 0.

for (int i=forward.length-1; i >= 0; i--){
    backward += forward[i];
}

Answer 3

Simple code snippet for your solution :

//pattern to be looked for 
    Pattern pattern = Pattern.compile("\\s"); 

    // splitting String with a pattern 
    String[] temp = pattern.split(str); 
    String result = ""; 

    // the string in reverse order. 
    for (int i = 0; i < temp.length; i++) { 
        if (i == temp.length - 1) 
            result = temp[i] + result; 
        else
            result = " " + temp[i] + result; 
    } 
    return result; 

For Working Example - Click Here .