JAVASCRIPT

a to z in js using while

var first = "a", last = "z";
for(var i = first.charCodeAt(0); i <= last.charCodeAt(0); i++) {
	document.write( eval("String.fromCharCode(" + i + ")") + " " );
}

a to z in js using while

for (var i = 65; i <= 90; i++) {
    $('#select_id_or_class').append('<option>' + String.fromCharCode(i) + '</option>');
}