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JavaScript: Create a new string of 4 copies of the last 3 characters of a given original string

JavaScript Basic: Exercise-58 with Solution

Write a JavaScript program to create a new string of 4 copies of the last 3 characters of a given original string. The length of the given string must be 3 and above.

Pictorial Presentation:

JavaScript: Create a new string of 4 copies of the last 3 characters of a given original string

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 of 4 copies of the last 3 characters of a given original string. The length of the given string must be 3 and above.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function newstring(str)
{
  if (str.length >= 3) {
    result_str = str.substring(str.length - 3);
    return result_str + result_str + result_str + result_str;
  }
  else
    return false;
}
console.log(newstring("Python 3.0"));
console.log(newstring("JS"));
console.log(newstring("JavaScript"));

Sample Output:

3.03.03.03.0
false
iptiptiptipt

Flowchart:

Flowchart: JavaScript - Create a new string of 4 copies of the last 3 characters of a given original string

ES6 Version:

function newstring(str)
{
  if (str.length >= 3) {
    result_str = str.substring(str.length - 3);
    return result_str + result_str + result_str + result_str;
  }
  else
    return false;
}
console.log(newstring("Python 3.0"));
console.log(newstring("JS"));
console.log(newstring("JavaScript"));

Live Demo:

See the Pen JavaScript - Create a new string of 4 copies of the last 3 characters of a string - basic-ex-57 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript program to create a new string of specified copies (positive number) of a given string.
Next: Write a JavaScript program to extract the first half of a string of even length.

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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