Dataweave 2.2 takeWhile 和 filter 有什么区别？

Question

%dw 2.0
import * from dw::core::Arrays
output application/json
var arr = [0,1,2,4,3]
---
arr filter $ <= 2

和

%dw 2.0
import * from dw::core::Arrays
output application/json
var arr = [0,1,2,4,3]
---
arr takeWhile $ <= 2

它们都给出相同的结果。有什么区别吗？

Answer 1

嗨 Dale 有一个区别 takeWhile 将停止使用第一个元素不满足条件的元素，这不是过滤器的情况，因此对于此示例 [0,2,4,3,1]

随着 TakeWhile

%dw 2.0
import * from dw::core::Arrays
output application/json
var arr = [0,2,4,3,1]
---
arr takeWhile $ <= 2

返回：

[
  0,
  2
]

带过滤器

%dw 2.0
import * from dw::core::Arrays
output application/json
var arr = [0,2,4,3,1]
---
arr filter $ <= 2

返回：

[
  0,
  2,
  1
]