var fruits = [“Banana”, “Orange”, “Apple”, “Mango”];<br /> undefined<br /> string = fruits.join(‘ ‘).toUpperCase();<br /> // Output”BANANA ORANGE APPLE MANGO”

const names = [‘Ali’, ‘Atta’, ‘Alex’, ‘John’];</p> <p>const lowercased = names.map(name => name.toLowerCase());</p> <p>console.log(lowercased);<br /> // [‘ali’, ‘atta’, ‘alex’, ‘john’]</p> <p>const uppercased = names.map(name => name.toUpperCase());</p> <p>console.log(uppercased);<br /> // [‘ALI’, ‘ATTA’, ‘ALEX’, ‘JOHN’]

var a = [‘this’,’is’,’test’];</p> <p>a.map(f=>{ return f.toUpperCase(); });

let myGreeting = ‘Hey there!’;</p> <p>console.log(myGreeting.toLowerCase());</p> <p>//output<br /> //hey there!

[“Foo”, “bar”].sort(Intl.Collator().compare); //[“bar”, “Foo”]