go - 在golang的不同位置初始化不同的 map 值

Question

我正在创建一个结构图来保存不同的信息。我正在使用的示例结构是:

type Test struct{
  Value1 string
  Value2 string
  Value3 string
  Value4 string
}

func main() {
  testMap := make(map[string]*Test) //using a pointer to map
  func2(testMap)
  //pass map to another function for more additions.
}

func func2 (testMap map[string]*Test) {
  a, b := getVal(); //get some random values
  res := concat(a,b) //basically create a string key based on values a and b
  testMap[res].value1 = a   //****
  testMap[res].value2 = b
  //do something else
  testMap[res].value3 = "hello"

}

我基本上是在尝试创建一个映射并在获取它们时向其添加值，但是我在 **** 行上收到 invalid memory address or nil pointer dereference 错误(参见代码对于 ***)。

Answer 1

尝试:

func func2 (testMap map[string]*Test) {
  a, b := getVal(); //get some random values
  res := concat(a,b) //basically create a string key based on values a and b
  testMap[res] = &Test{
     Value1: a,
     Value2: b,
     Value3: "string",
  }

}

或者如果你想先创建对象，然后填充值，试试

func func2 (testMap map[string]*Test) {
  a, b := getVal(); //get some random values
  res := concat(a,b) //basically create a string key based on values a and b
  testMap[res] = &Test{}
  testMap[res].value1 = a   //****
  testMap[res].value2 = b
  //do something else
  testMap[res].value3 = "hello"

}