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JavaScript: Create a new string from a given string changing the position of first and last characters

JavaScript Basic: Exercise-23 with Solution

Write a JavaScript program to create a new string from a given string changing the position of first and last characters. The string length must be greater than or equal to 1.

Pictorial Presentation:

JavaScript: Create a new string from a given string changing the position of first and last characters

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JavaScript program to create a new string from a given string changing the position of first and last characters.</title>
</head>
<body>
</body>
</html>

JavaScript Code:

function first_last(str1) 
  {
  if (str1.length <= 1)
  {
    return str1;
  }
  mid_char = str1.substring(1, str1.length - 1);
  return (str1.charAt(str1.length - 1)) + mid_char + str1.charAt(0);
}
console.log(first_last('a'));
console.log(first_last('ab'));
console.log(first_last('abc'));

Sample Output:

a
ba
cba

Flowchart:

Flowchart: JavaScript - Create a new string from a given string changing the position of first and last characters

ES6 Version:

function first_last(str1) 
  {
  if (str1.length <= 1)
  {
    return str1;
  }
  mid_char = str1.substring(1, str1.length - 1);
  return (str1.charAt(str1.length - 1)) + mid_char + str1.charAt(0);
}
console.log(first_last('a'));
console.log(first_last('ab'));
console.log(first_last('abc'));

Live Demo:

See the Pen JavaScript: position of first and last characters.: basic-ex-23 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript program to remove a character at the specified position of a given string and return the new string.
Next: Write a JavaScript program to create a new string from a given string with the first character of the given string added at the front and back.

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JavaScript: Tips of the Day

Classes/function constructors

class Person {
  constructor() {
    this.name = 'Owen';
  }
}

Person = class AnotherPerson {
  constructor() {
    this.name = 'Eddie';
  }
};

const member = new Person();
console.log(member.name);

We can set classes equal to other classes/function constructors. In this case, we set Person equal to AnotherPerson. The name on this constructor is Eddie, so the name property on the new Person instance member is "Eddie".

Ref: https://bit.ly/3jFRBje