JS for循环实现 My cats are called Bill, Jeff, Pete, Biggles, and Jasmin.

var cats = ['Bill', 'Jeff', 'Pete', 'Biggles', 'Jasmin'];
var info = 'My cats are called ';
for (var i = 0; i < cats.length; i++) {
  if (i === cats.length - 1) {
    info += 'and ' + cats[i] + '.';
  } else {
    info += cats[i] + ', ';
  }

}
console.log(info)