报告冗余的 Unit 表达式。

Kotlin 中的 Unit 可以用作不返回任何有意义的函数的返回类型。 Unit 类型只有一个可能的值,即 Unit 对象。

示例:


  fun redundantA(): Unit {
      return Unit // redundant, 'Unit' is returned by default and matches the expected return type
  }

  fun requiredA(condition: Boolean): Any {
      if (condition) return "hello"
      return Unit // explicit 'Unit' is required since the expected type is 'Any'
  }

  fun redundantB(condition: Boolean): Any = if (condition) {
      fun ancillary(): Int = 1
      println("${ancillary()}")
      Unit // redundant since the last expression is already of type 'Unit'
  } else {
      println("else")
  }

  fun requiredB(condition: Boolean): Any = if (condition) {
      1024
      Unit // required, otherwise '1024' (Int) would be the return value
  } else {
      println("else")
  }