I managed to split the string but how can I swap h with t and t with h in second half of string ?

public class Tollring3 {

   public static void main(String args[]) 
    { 
      
       String base = "httthhhtth";
      int half = base.length()/2;
       // int half = base.length() % 2 == 0 ? base.length()/2 : base.length()/2   1;
       String first = base.substring(0, half);
       String second = base.substring(half);
       System.out.println("Actual String :- " base);
       System.out.println(first);
       System.out.println(second);
       char[] c = second.toCharArray();

    // Replace with a "swap" function, if desired:
    char temp = c[0];
    c[0] = c[1];
    c[1] = temp;

    String swappedString = new String(c);
    System.out.println(swappedString);
    } 
}

How to swap h with t and t with h in second half of string

CodePudding user response：

This program splits a string into two halves, then swaps the first and second characters of the second half. public class Tollring3 {

   public static void main(String args[]) 
    { 
      
       String base = "httthhhtth";
      int half = base.length()/2;
       // int half = base.length() % 2 == 0 ? base.length()/2 : base.length()/2   1;
       String first = base.substring(0, half);
       String second = base.substring(half);
       System.out.println("Actual String :- " base);
       System.out.println(first);
       System.out.println(second);
       char[] c = second.toCharArray();

    // Replace with a "swap" function, if desired:
    char temp = c[0];
    c[0] = c[1];
    c[1] = temp;

    String swappedString = new String(c);
    System.out.println(swappedString);
    } 
}

CodePudding user response：

To do the replacement you need to iterate on the chars and use if to test what char it is

String base = "httthhhtth";
System.out.println(base);

char[] c = base.toCharArray();
for (int i = 0; i < c.length;   i) {
    if (i >= c.length / 2) { // check for change only in second half
        if (c[i] == 'h') {
            c[i] = 't';
        } else if (c[i] == 't') {
            c[i] = 'h';
        }
    }
}

String swappedString = new String(c);
System.out.println(swappedString);

httthhhtth
httthtthht

CodePudding user response：

You can define the swap function as follows:

String swap(String str) {
    char[] arr = str.toCharArray();
    char[] result = new char[arr.length];
    for (int i = 0; i < arr.length; i  )
        result[i] = arr[i] == 'h' ? 't' : arr[i] == 't' ? 'h' : arr[i];

    return new String(result);
}

In the function, we have

1. split the given string (second half) into a char array, arr.
2. created another char array, result of the same size.
3. iterates arr to store each character from arr into result while swapping h and t with each other.
4. finally returned a new String created out of result.

Full demo:

public class Main {
    public static void main(String args[]) {
        String base = "httthhhtth";
        int half = base.length() / 2;
        // int half = base.length() % 2 == 0 ? base.length()/2 : base.length()/2   1;
        String first = base.substring(0, half);
        String second = base.substring(half);
        System.out.println("Actual String :- "   base);
        System.out.println(first);
        System.out.println(second);

        String swappedString = swap(second);
        System.out.println(swappedString);
    }

    static String swap(String str) {
        char[] arr = str.toCharArray();
        char[] result = new char[arr.length];
        for (int i = 0; i < arr.length; i  )
            result[i] = arr[i] == 'h' ? 't' : arr[i] == 't' ? 'h' : arr[i];

        return new String(result);
    }
}

Output:

Actual String :- httthhhtth
httth
hhtth
tthht