造成这种恐慌的原因是什么？

Question

I am fairly new to Go, could someone help me diagnose this problem.

type ValidationStatus struct {
    Passed bool
    Errors map[string]*ValidationError
}

// ...

status := ValidationStatus{Passed: true}

// ...

status.Passed = false
fmt.Println(reflect.TypeOf(typeField.Name)) // string
fmt.Println(reflect.TypeOf(validationError)) // *validation.ValidationError   
status.Errors[typeField.Name] = validationError // Panic triggered here.

validationError is defined in the validation package. This code is in the same file as the struct.

This is the first time I have hit an issue like this, I think I may be using the map incorrectly but then I don't understand why this wouldn't cause a compile error so maybe a type issue? Any pointers to solve this would be much appreciated.

Answer 1

You didn't tell us what the error message was!

Map types

A new, empty map value is made using the built-in function make, which takes the map type and an optional capacity hint as arguments:

make(map[string]int)
make(map[string]int, 100)

For example,

status := ValidationStatus{Passed: true, Errors: make(map[string]*ValidationError)}