convert array to lowercase in javascript code example

Example 1: convert an array to uppercase or lowercase js

var fruits = ["Banana", "Orange", "Apple", "Mango"];
undefined
string = fruits.join(' ').toUpperCase();
// Output"BANANA ORANGE APPLE MANGO"

Example 2: how to convert array to uppercase in javascript

var a = ['this','is','test'];

a.map(f=>{ return f.toUpperCase(); });