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JavaScript: Create a new string from a given string taking the last 3 characters and added at both the front and back

JavaScript Basic: Exercise-26 with Solution

Write a JavaScript program to create a new string from a given string taking the last 3 characters and added at both the front and back. The string length must be 3 or more.

Pictorial Presentation:

JavaScript: Create a new string from a given string taking the last 3 characters and added at both the front and back

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 taking the last 3 characters and added at both the front and back. The string length must be 3 or more.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function front_back3(str)
 {
  if (str.length>=3)
   {
   str_len = 3;
 
  back = str.substring(str.length-3);
   return back + str + back;
 }
   else
     return false;
 }
console.log(front_back3("abc"));
console.log(front_back3("ab"));
console.log(front_back3("abcd"));

Sample Output:

abcabcabc
false
bcdabcdbcd

Flowchart:

Flowchart: JavaScript - Create a new string from a given string taking the last 3 characters and added at both the front and back

ES6 Version:

function front_back3(str)
 {
  if (str.length>=3)
   {
   str_len = 3;
 
  back = str.substring(str.length-3);
   return back + str + back;
 }
   else
     return false;
 }
console.log(front_back3("abc"));
console.log(front_back3("ab"));
console.log(front_back3("abcd"));

Live Demo:

See the Pen JavaScript: added characters added at both the front and back-basic- ex-25 by w3resource (@w3resource) on CodePen.


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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