Learn to write Java program to reverse a String. We will first see how to reverse string and the we will also see how to reverse the words in String.
It’s common puzzle asked in Java interviews at beginner level. Let’s memorize these solutions for quick recall.
1. Java program to reverse string
You can reverse a string by character easily, using a StringBuilder.reverse()
method.
String blogName = "HowToDoInJava.com"; String reverse = new StringBuilder(string).reverse(); System.out.println("Original String -> " + blogName); System.out.println("Reverse String -> " + reverse); Output: Original String -> HowToDoInJava.com Reverse String -> moc.avaJnIoDoTwoH
Java Program to reverse string by words
While reversing string content by words, most natural way is to use a StringTokenizer
and a Stack
. As you are aware that Stack
is a class that implements an easy-to-use last-in, first-out (LIFO) stack of objects.
] String description = "Java technology blog for smart java concepts and coding practices"; // reverse string builder StringBuilder reverseString = new StringBuilder(); // Put words from String in Stack Stack<String> myStack = new Stack<>(); StringTokenizer tokenizer = new StringTokenizer(description, " "); while (tokenizer.hasMoreTokens()) { myStack.push(tokenizer.nextToken()); } //Pop each word from stack and append in builder while (!myStack.empty()) { reverseString.append(myStack.pop() + " "); } System.out.println(reverseString.toString()); Output: practices coding and concepts java smart for blog technology Java
Happy Learning !!
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