.splice 确实返回已删除的项目.但是，它也会在内部操作数组.这样可以防止您将任何内容链接到.splice.您必须进行两个单独的调用:

.splice does return the removed item. However, it also manipulates the array internally. This prevents you from chaining anything to .splice; you must do two separate calls:

value = value.split(',');
value.splice(1, 1);
console.log(value.join(','));

如果执行value = value.splice(...)，则value被覆盖，并且数组丢失！

If you do value = value.splice(...), value is overridden, and the array is lost!