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JavaScript: Input a string and converts upper case letters to lower and vice versa

JavaScript String: Exercise-10 with Solution

Write a JavaScript function that takes a string which has lower and upper case letters as a parameter and converts upper case letters to lower case, and lower case letters to upper case.

Test Data:
console.log(swapcase('AaBbc'));
"aAbBC"

Pictorial Presentation:

JavaScript: Input a string and converts upper case letters to lower and vice versa

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS swap case</title>
</head>
<body>
</body>
</html>

JavaScript Code:

swapcase = function swapcase(str) {
        return str.replace(/([a-z]+)|([A-Z]+)/g, function(match, chr) {
            return chr ? match.toUpperCase() : match.toLowerCase();
        });
    }
console.log(swapcase('AaBbc'));

Sample Output:

aAbBC

Flowchart:

Flowchart: JavaScript- Input a string and converts upper case letters to lower and vice versa

Live Demo:

See the Pen JavaScript Input a string and converts upper case letters to lower and vice versa - string-ex-10 by w3resource (@w3resource) on CodePen.


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Next: Write a JavaScript function to convert a string into camel case.

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JavaScript: Tips of the Day

Converts a given string into an array of words

Example:

const words = (str, pattern = /[^a-zA-Z-]+/) => str.split(pattern).filter(Boolean);
console.log(words('I love javaScript!!')); // ["I", "love", "javaScript"]
console.log(words('python, javaScript & coffee')); // ["python", "javaScript", "coffee"]

Output:

["I", "love", "javaScript"]
["python", "javaScript", "coffee"]