Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

JavaScript: Swap the case of each character of a string, upper case to lower and vice versa

JavaScript Array: Exercise-9 with Solution

Write a JavaScript program which accept a string as input and swap the case of each character. For example if you input 'The Quick Brown Fox' the output should be 'tHE qUICK bROWN fOX'.

Pictorial Presentation:

JavaScript: Swap the case of each character of a string, upper case to lower and vice versa

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Swap the case of each character of a string</title>
</head>
<body>
</body>
</html>

JavaScript Code:

var str = 'c';
var UPPER = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var LOWER = 'abcdefghijklmnopqrstuvwxyz';
var result = [];
  
  for(var x=0; x<str.length; x++)
  {
    if(UPPER.indexOf(str[x]) !== -1)
    {
      result.push(str[x].toLowerCase());
    }
    else if(LOWER.indexOf(str[x]) !== -1)
    {
      result.push(str[x].toUpperCase());
    }
    else 
    {
      result.push(str[x]);
    }
  }
console.log(result.join(''));

Sample Output:

C

Flowchart:

Flowchart: JavaScript: Display the colors entered in an array by a specific format

ES6 Version:

var str = 'c';
const UPPER = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
const LOWER = 'abcdefghijklmnopqrstuvwxyz';
const result = [];
  
  for(let x=0; x<str.length; x++)
  {
    if(UPPER.includes(str[x]))
    {
      result.push(str[x].toLowerCase());
    }
    else if(LOWER.includes(str[x]))
    {
      result.push(str[x].toUpperCase());
    }
    else 
    {
      result.push(str[x]);
    }
  }
console.log(result.join(''));

Live Demo:

See the Pen JavaScript - Swap the case of each character of a string, upper case to lower and vice versa- array-ex- 9 by w3resource (@w3resource) on CodePen.


Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to find the most frequent item of an array.
Next: Write a JavaScript program which prints the elements of the following array.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04