foreach-modification-during-iteration.js

var ary = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
for each (let v in ary) {
	console.log('v is', typeof v, ary.indexOf(v));
	ary.splice(ary.indexOf(v), 1);
}
var ary2 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
for (var n in ary2) {
	var v = ary2[n];
	console.log('n is', n, 'v is', typeof v, ary2.indexOf(v));
	ary2.splice(ary2.indexOf(v), 1);
}