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:

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:

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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JavaScript: Tips of the Day
var functionName = function() {} vs function functionName() {}
The difference is that functionOne is a function expression and so only defined when that line is reached, whereas functionTwo is a function declaration and is defined as soon as its surrounding function or script is executed (due to hoisting).
For example, a function expression:
// TypeError: functionOne is not a function functionOne(); var functionOne = function() { console.log("Hello!"); };
Historically, function declarations defined within blocks were handled inconsistently between browsers. Strict mode (introduced in ES5) resolved this by scoping function declarations to their enclosing block.
'use strict'; { // note this block! function functionThree() { console.log("Hello!"); } } functionThree(); // ReferenceError
Ref: https://bit.ly/2zMAj1O
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