class LetterByLetter {
 
	public static void changeString(String str1, String str2) {
		System.out.println(str1);
		if (str1.length() == str2.length()) {
			char[] c1 = str1.toCharArray();
			char[] c2 = str2.toCharArray();
			for (int j = 0; j < str1.length(); j++) {
				if (c1[j] != c2[j]) {
					c1[j] = c2[j];
					System.out.println(c1);
				}
			}
		} else
			System.out.println("Strings are not of same length.");
	}
 
	public static void main(String[] args) {
		changeString("floor", "brake");
		System.out.println();
		changeString("wood", "book");
		System.out.println();
		changeString("a fall to the floor", "braking the door in");
	}
}

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