Why Can't I Parse JSON into My Go Struct?

Parsing JSON into Go Structs

Parsing JSON into Go structs allows for convenient access to structured data configurations. Although the code snippet you provided compiles without errors, it fails to populate the struct fields with correct values.

Addressing the Issue

The problem lies in the exported status of your struct elements. In Go, for a struct element to be accessible during encoding/decoding by the JSON package, it must start with an uppercase letter. This ensures that the element can be accessed outside its package.

Correcting the Code

To fix the issue, you need to make the first letter of each struct element uppercase. The corrected code would look like this:

var settings struct {
    ServerMode bool `json:"serverMode"`
    SourceDir  string `json:"sourceDir"`
    TargetDir  string `json:"targetDir"`
}

By capitalizing the struct element names, you are essentially exporting them, making them accessible for JSON encoding and decoding. Now, when the JSON parser encounters the corresponding field names in the JSON file, it will correctly assign the parsed values to the struct fields.

Expected Output

After making this correction, your program should now print the correct settings values as specified in the config.json file:

true . .

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