JavaScript Program to Reverse a String

Example 1: Reverse a String Using for Loop

Output

Enter a string: hello world
dlrow olleh

In the above program, the user is prompted to enter a string. That string is passed to the reverseString() function.

Inside the reverseString() function,

• An empty newString variable is created.
• The for loop is used to iterate over the strings. During the first iteration, str.length - 1 gives the position of the last element. That element is added to the newString variable.
  This process continues for all the string elements.
• The value of i decreases in each iteration and continues until it becomes 0.

Example 2: Reverse a String Using built-in Methods

Output

Enter a string: hello
olleh

In the above program, the built-in methods are used to reverse a string.

• First, the string is split into individual array elements using the split() method. str.split("") gives ["h", "e", "l", "l", "o"].
• The string elements are reversed using the reverse() method. arrayStrings.reverse() gives ["o", "l", "l", "e", "h"].
• The reversed string elements are joined into a single string using the join() method. reverseArray.join("") gives olleh.