// the array to be sorted
var list = ['Delta', 'alpha', 'CHARLIE', 'bravo'];
// temporary array holds objects with position and sort-value
var mapped = list.map(function(el, i) {
return { index: i, value: el.toLowerCase() };
})
// sorting the mapped array containing the reduced values
mapped.sort(function(a, b) {
if (a.value > b.value) {
return 1;
}
if (a.value < b.value) {
return -1;
}
return 0;
});
// container for the resulting order
var result = mapped.map(function(el){
return list[el.index];
});