Vue: children component not update when change Array props in parent

[JJJYY]

Version

2.5.16

Reproduction link

https://jsfiddle.net/jesse_y/obbL7s1k/

Steps to reproduce

1. click change, children component not update
2. click update, children component update

What is expected?

click change, children component update

What is actually happening?

children component not update

---

maybe not a bug, I test 2.* and 1.*(not all), it not work in those version.
is it a bug? if not why?
thanks for your time.

[Justineo]

this.numbers[0]++

is equal to

this.numbers[0] = this.numbers[0] + 1

which is already discussed in the guide.

You should do this instead:

this.$set(this.numbers, 0, this.numbers[0] + 1)

[JJJYY]

@Justineo thanks!