Replace characters in a string, without using string replace() method [closed]

Answer 1

You can split on "car" and then concatenate with adding "bike"

import java.util.*;

class StringTest 
{
    public static void main(String[] args)
    {
        String originalString = "This car is my car";
        String replacedString = replaceMethod(originalString, "car", "bike");
        System.out.println(replacedString);
    }

    static String replaceMethod(String str, String from, String to) 
    {
        String[] arr = str.split(from);
        StringBuilder output = new StringBuilder();

        int i = 0;
        for (; i < arr.length - 1; i++)
        output.append(arr[i]).append(to);

        output.append(arr[i]);
        if (str.substring(str.lastIndexOf(" ")).equalsIgnoreCase(" " + from))
            output.append(to);

        return output.toString();
    }
}

originalString

This car is my car

output

This bike is my bike

Thanks for Mr. Polywhirl for his help.