Return all values from array in lowercase using for loop instead of map

Question

var sorted = words.map(function(value) {     return value.toLowerCase(); }).sort(); 

This code returns all values from words array in lowercase and sorts them, but I wanna do the same with a for loop but I can't.

I tried:

for (var i = 0; i < words.length; i++) {   sorted = [];   sorted.push(words[i].toLowerCase()); }; 

Answer 1

You can also now achieve this very simply by using an arrow function and the map() method of the Array:

var words = ['Foo','Bar','Fizz','Buzz'].map(v => v.toLowerCase());  console.log(words);

Note that map() will only work in browsers which support ES2015. In other words, anything except IE8 and lower.

Similarly, arrow functions will not work at all in IE. For a legacy browser safe version you would need to use an anonymous function:

var words = ['Foo','Bar','Fizz','Buzz'].map(function(v) {    return v.toLowerCase();  });  console.log(words);

Answer 2

push is overused.

for (var i = 0, L=words.length ; i < L; i++) {   sorted[i]=words[i].toLowerCase(); } 

If you want fast and have a very large array of words, call toLowerCase once-

sorted=words.join('|').toLowerCase().split('|');