二进制运算符'！='不能应用于两个'[[String]]'操作数 [英] Binary operator '!=' cannot be applied to two '[[String]]' operands

问题描述

我有一个数组数组，需要过滤掉其中的一个特定数组.但是，使用以下代码时，出现二进制运算符'！='不能应用于两个'[[String]]'操作数"的问题.

I have an array of arrays and need to filter out one of the specific arrays in it. However, when using the following code, I get the issue "Binary operator '!=' cannot be applied to two '[[String]]' operands".

var arrayOfArrays = [[[String]]]()
var specificArray = [[String]]()

arrayOfArrays = arrayOfArrays.filter{$0 != specificArray}

我认为这曾经在半年前起作用...

I think this used to work like half a year ago...

推荐答案

如评论中所述， Swift数组不符合Equatable ，因此 [[T]]！= [[T]] 不起作用，因为它要求 [T] 为Equatable.您可以使用 elementsEqual(_:by:) ，它允许使用自定义的相等函数比较元素，而不会变得相等:

As mentioned in the comments, Swift Arrays don't conform to Equatable so [[T]] != [[T]] does not work because it requires [T] to be Equatable. You could use elementsEqual(_:by:) instead, which allows comparing elements using a custom equality function, without being Equatable:

arrayOfArrays = arrayOfArrays.filter { !$0.elementsEqual(specificArray, by: ==) }

(注意:感谢 SE-0143"条件一致" ，一旦Swift 4发布，就不再需要此解决方法.)

(Note: Thanks to SE-0143 "Conditional conformances", this workaround is no longer needed once Swift 4 is released.)

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